Watson's Biblical & Theological Dictionary 
a mysterious kind of science, delivered to the ancient Jews, as they pretend, by revelation, and transmitted by oral tradition to those of our times; serving for the interpretation of the books both of nature and Scripture. The word is variously written, as Cabala, Caballa, Kabbala, Kabala, Cabalistica, Ars Cabala, and Gaballa. It is originally Hebrew, קבלה , and properly signifies reception; formed from the verb קכל , to receive by tradition, or from father to son; especially in the Chaldee and Rabbinical Hebrew. Cabbala, then, primarily, denotes any sentiment, opinion, usage, or explication of Scripture, transmitted from father to son. In this sense the word cabbala is not only applied to the whole art, but also to each operation performed according to the rules of that art. Thus it is, rabbi Jacob Ben Ascher, surnamed Baal-Hatturim, is said to have compiled most of the cabbalas invented on the books of Moses before his time. As to the origin of the cabbala, the Jews relate many marvellous tales. They derive the mysteries contained in it from Adam; and assert, that whilst the first man was in paradise, the angel Raphael brought him a book from heaven, which contained the doctrines of heavenly wisdom; and that when Adam received this book, angels came down from heaven to learn its contents; but that he refused to admit them to the knowledge of sacred things, intrusted to himself alone: that, after the fall, this book was taken back into heaven; that, after many prayers and tears, God restored it to Adam; and that it passed from Adam to Seth. The Jewish fables farther relate, that the book being lost, and the mysteries contained in it almost forgotten, in the degenerate age preceding the flood, they were restored by special revelation to Abraham, who transmitted them to writing in the book "Jezirah;" and that the revelation was renewed to Moses, who received a traditionary and mystical, as well as a written and preceptive, law from God. Accordingly, the Jews believe that God gave to Moses on Mount Sinai, not only the law, but also the explication of that law; and that Moses, after his coming down, retiring to his tent, rehearsed to Aaron both the one and the other. When he had done, the sons of Aaron, Eleazar and Ithamar, were introduced to a second rehearsal. This being over, the seventy elders that composed the sanhedrim were admitted; and, lastly, the people, as many as pleased; to all of whom Moses again repeated both the law and explanation, as he received them from God: so that Aaron heard it four times, his sons thrice, the elders twice, and the people once. Now, of the two things which Moses taught them, the laws and the explanation, only the first were committed to writing; which is what we have in Exodus, Leviticus, and Numbers. As to the second, or the explication of those laws, they were contented to impress it well in their memory, to teach it their children; they to theirs, &c. Hence the first part they call simply the law, or the written law; the second, the oral law, or cabbala. Such is the original notion of the cabbala.
2. The cabbala being again lost amidst the calamities of the Babylonish captivity, was once more revealed to Esdras; and it is said to have been preserved in Egypt, and transmitted to posterity through the hands of Simeon Ben Setach, Elkanah, Akibha, Simeon Ben Jochai, and others. The only warrantable inference from these accounts, which bear the obvious marks of fiction, is, that the cabbalistic doctrine obtained early credit among the Jews as a part of their sacred tradition, and was transmitted under this notion, by the Jews in Egypt to their brethren in Palestine. Under the sanction of ancient names, many fictitious writings were produced, which greatly contributed to the spreading of this mystical system. Among these were "Sepher Happeliah," or the book of wonders; "Sepher Hakkaneh," or the book of the pen; and "Sepher Habbahir," or the book of light. The first unfolds many doctrines said to have been delivered by Elias to the rabbi Elkanah; the second contains mystical commentaries on the divine commands; and the third illustrates the most sublime mysteries. Among the profound doctors who, beside the study of tradition, cultivated with great industry the cabbalistic philosophy, the most celebrated persons are the rabbis Akibba, who lived soon after the destruction of Jerusalem, and Simeon Ben Jochai, who flourished in the second century. To the former is ascribed the book entitled "Jezirah," concerning the creation; and to the latter, the book "Sohar," or brightness; and these are the principal sources from which we derive our knowledge of the cabbala.
3. That this system of the cabbalistic philosophy, which we may consider as the acroamatic, esoretic, or concealed doctrine of the Jews, by way of contradistinction from the exoretic or popular doctrine, was not of Hebrew origin, we may conclude with a very great degree of probability, from the total dissimilarity of its abstruse and mysterious doctrines to the simple principles of religion taught in the Mosaic law; and that it was borrowed from the Egyptian schools, will sufficiently appear from a comparison of its tenets with those of the oriental and Alexandrian philosophy. Many writers have, indeed, imagined that they have found in the cabbalistic dogmas a near resemblance of the doctrines of Christianity; and they have thought that the fundamental principles of this mystical system were derived from divine revelation. This opinion, however, may be traced up to a prejudice which originated with the Jews, and passed from them to the Christian fathers, by which they were led to ascribe all Pagan wisdom to a Hebrew origin: a notion which very probably took its rise in Egypt, when Pagan tenets first crept in among the Jews. Philo, Josephus, and other learned Jews, in order to flatter their own vanity, and that of their countrymen, industriously propagated this opinion; and the more learned fathers of the Christian church, who entertained a high opinion of the Platonic philosophy, hastily adopted it, from an imagination that if they could trace back the most valuable doctrines of Paganism to a Hebrew origin, this could not fail to recommend the Jewish and Christian religions to the attention of the Gentile philosophers. Many learned moderns, relying implicitly upon these authorities, have maintained the same opinion; and have thence been inclined to credit the report of the divine original of the Jewish cabbala. But the opinion is unfounded; and the cabbalistic system is essentially inconsistent with the pure doctrine of divine revelation. The true state of the case seems to be, that during the prophetic ages, the traditions of the Jews consisted in a simple explanation of those divine truths which the prophets delivered, or their law exhibited, under the veil of emblems. After this period, when the sects of the Essenes and Therapeutae were formed in Egypt, foreign tenets and institutions were borrowed from the Egyptians and Greeks; and, in the form of allegorical interpretations of the law, were admitted into what might then be called the Jewish mysteries, or secret doctrines. These innovations chiefly consisted in certain dogmas concerning God and divine things, at this time received in the Egyptian schools; particularly at Alexandria, where the Platonic and Pythagorean doctrines on these subjects had been blended with the oriental philosophy. The Jewish mysteries, thus enlarged by the accession of Pagan dogmas, were conveyed from Egypt to Palestine, at the time when the Pharisees, who had been driven into Egypt under Hyrcanus, returned with many other Jews into their own country. From this time the cabbalistic mysteries continued to be taught in the Jewish schools; but at length they were adulterated by a mixture of Peripatetic doctrines, and other tenets. These mysteries were not, probably, reduced to any systematic forms in writing, till after the dispersion of the Jews; when, in consequence of their national calamities, they became apprehensive that those sacred treasures would be corrupted or lost. In preceding periods, the cabbalistic doctrines underwent various corruptions, particularly from the prevalence of the Aristotelian philosophy. The similarity, or rather the coincidence, of the cabbalistic, Alexandrian, and oriental philosophy, will be sufficiently evinced by briefly stating the common tenets in which these different systems agreed. They are as follow:—"All things are derived by emanation from one principle; and this principle is God. From him a substantial power immediately proceeds, which is the image of God, and the source of all subsequent emanations. This second principle sends forth, by the energy of emanation, other natures, which are more or less perfect, according to their different degrees of distance, in the scale of emanation, from the first source of existence, and which constitute different worlds or orders of being, all united to the eternal power from which they proceed. Matter is nothing more than the most remote effect of the emanative energy of the Deity.
The material world receives its form from the immediate agency of powers far beneath the first source of being. Evil is the necessary effect of the imperfection of matter. Human souls are distant emanations from Deity; and, after they are liberated from their material vehicles, will return, through various stages of purification, to the fountain whence they first proceeded. From this brief view it appears, that the cabbalistic system, which is the offspring of the other two, is a fanatical kind of philosophy, originating in defect of judgment and eccentricity of imagination, and tending to produce a wild and pernicious enthusiasm.
4. Among the explications of the law which are furnished by the cabbala, and which, in reality, are little else but the several interpretations and decisions of the rabbins on the laws of Moses, some are mystical; consisting of odd abstruse significations given to a word, or even to the letters whereof it is composed: whence, by different combinations, they draw meanings from Scripture very different from those it seems naturally to import. The art of interpreting Scripture after this manner is called more particularly
cabbala; and it is in this last sense the word is more ordinarily used among us. This cabbala, called also artificial cabbala, to distinguish it from the first kind, or simple tradition, is divided into three sorts. The first, called gematria, consists in taking letters as figures, or arithmetical numbers, and explaining each word by the arithmetical value of the letters whereof it is composed; which is done various ways: the second is called notaricon, and consists either in taking each letter of a word for an entire diction, or in making one entire diction out of the initial letters of many: the third kind, called themurah, that is, changing, consists in changing and transposing the letters of a word; which is done various ways. The generality of the Jews prefer the cabbala to the literal Scripture; comparing the former to the sparkling lustre of a precious stone, and the latter to the fainter glimmering of a candle. The cabbala only differs from masorah, as the latter denotes the science of reading the Scripture; the former, of interpreting it. Both are supposed to have been handed down from generation to generation by oral tradition only, till at length the readings were fixed by the vowels and accents, as the interpretations were by the gemara.
5. Cabbala is also applied to the use, or rather abuse, which visionaries and enthusiasts make of Scripture, for discovering futurity by the study and consideration of the combination of certain words, letters, and numbers, in the sacred writings. All the words, terms, magic figures, numbers, letters, charms, &c, used in the Jewish magic, as also in the hermetical science, are comprised under this species of cabbala; which professes to teach the art of curing diseases, and performing other wonders, by means of certain arrangements of sacred letters and words. But it is only the Christians that call it by this name, on account of the resemblance this art bears to the explications of the Jewish cabbala: for the Jews never used the word cabbala in any such sense; but ever with the utmost respect and veneration. It is not, however, the magic of the Jews alone which we call cabbala: but the word is also used for any kind of magic.
Charles Buck Theological Dictionary 
A Hebrew word, signifying tradition: it is used for a mysterious kind of science pretended to have been delivered by revelation to the ancient Jews, and transmitted by oral tradition to those of our times; serving for interpretation of the books both of nature and Scripture.