From BiblePortal Wikipedia

Wilson's Dictionary of Bible Types [1]

(c) The threes of the Bible represent triads of completeness.

Sometimes it is a triad of good, and sometimes of evil.

- the Trinity of Heaven is the Father, the Son and the Holy Spirit.

- the trinity of evil is the devil, the antichrist and the false prophet.

- the trinity of blessing is grace, mercy and peace.

- the trinity of wickedness is the world, the flesh and the devil.

It is interesting to note that the books of first and second Thessalonians are built largely around three-fold statements.

Chapter1:3, "The work of faith, and labor of love, and patience of hope."

Chapter1:5, "in word . . . in power, and in the Holy Spirit."

Chapter1:9,10, "ye turned . . . to serve . . . and to wait."

Chapter2:10, "Holily, justly and unblameably."

The many triads in both of these books show how fully and completely GOD has provided for His own people for their daily living.

Man's life also consists of three elements of time - the past. the present and the future.

Our salvation is three-fold. We have been delivered, we are being delivered, and we shall be delivered. (  2 Corinthians 1:10).

In Bible study there are three time elements as found in  Revelation 1:19. John was to write the things he had already seen, and the things that are now transpiring, and the things that are still in the future and shall yet come to pass.

 Joshua 1:11 (c) As Jordan was typical of death, the three days are typical of the resurrection assured to the people of Israel. They were to pass through Jordan and come out safely on the third day.

 Matthew 12:40 (b) No doubt this is typical of the resurrection, for it was on the third day that Jesus rose.

 Matthew 13:33 (b) Probably this is typical of life, for the meal was good food, ready to impart life to those who ate it. (See under "LEAVEN").

The thought in the number three also indicates the fact that Christ who was typified as meal in the Old Testament would be the living CHRIST, raised from the dead, to feed His people constantly. Some think it represents the Father, the Son and the Holy Spirit. Others suggest it refers to prophetical, historical and doctrinal aspects of the Bible.

Hawker's Poor Man's Concordance And Dictionary [2]

I pause over this number to make a short observation concerning what we read of the sacred Three in one described by the Apostle John, and which bears a beautiful and glorious correspondence to all the testimonies of the holy writers in the Bible. "For there are three that bear record in Heaven, the Father, the Son and Holy Ghost, and these three are one." ( 1 John 5:7) It is somewhat remarkable that the word Trinity is never used by any of the sacred writers: that is to say, by the translators of the Bible into our mother tongue, while they are so express in numberless instances, giving the sum and substance of it. Evidently many of the old Rabbi gave distinct names to each glorious person of the Godhead as their writings testify. They called the Father, Jehovah and the Son, the Word or Memur: and the Holy Ghost, Ruach. And they expressed the union of those Three Glorious persons by the word Shalithith, which is as near as possible the word Trinity. It must be confessed, (for it maybe be very safely allowed without the smallest injury to the true faith,) that there are numbers among the Jews of modern times, who from the ignorance of their mind and blinded understanding, are looking for the Messiah in the simple humanity of the man, and know nothing of JEHOVAH in his threefold personality of character. But these do by no means invalidate the true faith, any more than Socinians and Arians, by their denial of the GODHEAD of Christ. The ancient descendants of Abraham, and it is to be hoped the modern stock of Israel, though overlooking the time, have lost not sight of his Almighty person. They know what the prophet said to be true concerning the Messiah, and expected him in that character. "Behold, your God shall come and save you." ( Isaiah 35:4)

Vine's Expository Dictionary of NT Words [3]

1: Τρέχω (Strong'S #5143 — Verb — treis — trekh'-o )

is regarded by many as a number sometimes symbolically indicating fullness of testimony or manifestation, as in the three persons in the Godhead, cp.  1—Timothy 5:19;  Hebrews 10:28; the mention in  1—John 5:7 is in a verse which forms no part of the original; no Greek ms. earlier than the 14th century contained it; no version earlier than the 5th cent. in any other language contains it, nor is it quoted by any of the Greek or Latin "Fathers" in their writings on the Trinty. That there are those who bear witness in Heaven is not borne out by any other Scripture. It must be regarded as the interpolation of a copyist.

 Mark 9:31 10:34  Matthew 17:23 20:19 Luke 9:22 18:33 Acts 10:40Thrice.

American Tract Society Bible Dictionary [4]

The phrase "three days and three nights,"  Matthew 12:40 , was equivalent in Hebrew to the English "three days;" the Jews employing the expression "a day and a night" to denote our "day" of twentyfour hours. Nor did "three days,"  1 Samuel 30:13 , literally "this third day," according to their usage, necessarily include the whole of three days, but a part of three days, a continuous period including one whole day of twenty-four hours, and a portion of the day preceding it and the day following it. Compare  Genesis 7:12,17   1 Samuel 30:12-13 .

King James Dictionary [5]

Three a. L. tres.

1. Two and one.

I offer thee three things.  2 Samuel 24 .

2. It is often used like other adjectives, without the noun to which it refers.

Abishai--attained not to the first three.  2 Samuel 23

3. Proverbially, a small number.

Away, thou three-inched fool. I believe obsolete.

Webster's Dictionary [6]

(1): ( n.) The number greater by a unit than two; three units or objects.

(2): ( a.) One more than two; two and one.

(3): ( n.) A symbol representing three units, as 3 or iii.

Hastings' Dictionary of the Bible [7]

THREE . See Number, § 7 .

Morrish Bible Dictionary [8]

See Numbers As Symbols

Hastings' Dictionary of the New Testament [9]

See Numbers.

International Standard Bible Encyclopedia [10]

( שׁלשׁ , shālōsh  ; τρεῖς , treı́s ). See Number .