From BiblePortal Wikipedia

Fausset's Bible Dictionary [1]

Jerusalem's citizens, captives at Sepharad, shall return to occupy the city and southern Judaea ( Obadiah 1:20). Jerome's Hebrew tutor thought Sepharad was on the Bosphorus. Jerome derives it from an Assyrian word "limit," i.e. scattered in all regions abroad (so  James 1:1). The modern Jews think Spain. As Ζarephath , a Phoenician city, was mentioned in the previous clause, Sepharad is probably some Phoenician colony in Spain or some other place in the far West (Compare  Joel 3:6 , To Which Obadiah Refers) . C Ρa Rad occurs before Ionia and Greece in a cuneiform inscription giving a list of the Persian tribes (See also Niebuhr, Reiseb. 2:31). Also in Darius' epitaph at Nakshi Rustam, 1:28, before Ionia in the Behistun inscription (i. 15). Thus, it would be Sardis (The Greeks Omitting The -Ph ) in Lydia. In favor of Spain is the fact that the Spanish Jews are called Sephardim , the German Jews Αshkenazim .

Hastings' Dictionary of the Bible [2]

SEPHARAD . A country in which was a community of exiles from Judah in the days of the prophet Obadiah (  Obadiah 1:20 ). It is probably to be understood as Sparda ( Çparda ), a Persian province of Asia Minor, not definitely treated in its earliest use, but in the time of the Seleucidæ employed for Asia Minor as a whole. Cf. Obadiah, p. 664 b .

J. F. McCurdy.

Morrish Bible Dictionary [3]

Place where the Jews were in captivity, but from whence they would be brought to possess 'the cities of the south.'  Obadiah 20 . The LXX has 'as far as Ephratha'; and the Vulgate 'in Bosphoro.' Jerome considered the word signified 'boundary,' and referred to the dispersion of the Jews in any region.

Smith's Bible Dictionary [4]

Seph'arad. (Separated). A name, which occurs in  Obadiah 1:20 only. Its situation has always been a matter of uncertainty.

American Tract Society Bible Dictionary [5]

A place in Asia Minor near the Bosphorus, to which Jewish captives were conveyed,  Obadiah 1:20 .

Holman Bible Dictionary [6]

 Genesis 10:20

Easton's Bible Dictionary [7]

 Obadiah 1:20

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [8]

(Heb. Sepharad', סְפָרָד , meaning, if Heb., Separated; Targ. אַסְפִמְיָא , i.e. Ispamia; Sept. Ἕως Ε᾿Φραθᾶ ; Vulg. In Bosporo ) , a name which occurs in  Obadiah 1:20 only, as that of a place in which the Jews of Jerusalem were then held in captivity, and whence they were to return to possess the cities of the south. Its situation has always been a matter of uncertainty, and cannot even now be said to be settled.

1. The reading of the Sept. given above, and followed by the Arabic Version, is probably a mere conjecture, though it may point to a modified form of the name in the then original, viz. Sepharath. In Jerome's copy of the Sept. it appears to have been Εὐφράτης , since ( Comm. In Abd. ) he renders their version of the verse Transmigratio Ierusalem Usque Euphrathem. This is certainly extremely ingenious, but will hardly hold when we turn it back into Hebrew.

2. The reading of the Vulgate, Bosporus (obtained by taking the prefixed preposition as part of the name בספרד and at the same time rejecting the final D), was adopted by Jerome from his Jewish instructor, who considered it to be "the place to which Hadrian had transported the captives from Jerusalem" ( Comm. In Abd. ) . This interpretation Jerome did not accept, but preferred rather to treat Sepharad as connected with a similar Assyrian word signifying a "boundary," and to consider the passage as denoting the dispersion of the Jews into all regions. We have no means of knowing to which Bosporus Jerome's teacher alluded the Cimmerian or the Thracian. If the former (Strait of Yenikale), which was in Iberia, it is not impossible that this rabbi, as ignorant of geography outside of the Holy Land as most of his brethren, confounded it with Iberia in Spain, and thus agreed with the rest of the Jews whose opinions have come down to us. If the latter (Strait of Constantinople), then he may be taken as confirming the most modern opinion (noticed below), that Sepharad was Sardis in Lydia.

3. The Targum Jonathan (see above) and the Peshito-Syriac, and from them the modern Jews, interpret Sepharad as Spain (Ispamia and Ispania), one common variation of which name, Hesperia, does certainly bear considerable resemblance to Sepharad; and so deeply has this taken root that at the present day the Spanish Jews, who form the chief of the two great sections into which the Jewish nation is divided, are called by the Jews themselves the Sephardim, German Jews, being known as the Ashkenazim. It is difficult to suppose that either of these can be the true explanation of Sepharad. The prophecy of Obadiah has every appearance of referring to the destruction of Jerusalem by Nebuchadnezzar, and there is no reason to believe that any Jews had been at that early date transported to Spain.

4. Others have suggested the identity of Sepharad with Sipphara in Mesopotamia (Hardt, Sipphara Babylonioe [Helmst. 1708]), but that is more probably Sepharvaim.

5. The name has perhaps been discovered in the cuneiform Persian inscriptions of Naksh-i-Rustum and Behistun (see Burnouf. Mem. Sur Deux Inscr. Cuneif. 1836, p. 147), and also in a list of Asiatic nations given by Niebuhr ( Reiseb. 2, pl. 31). In the latter it occurs between Ka Ta Pa TUK (Cappadocia) and Ta UNA (Ionia). De Sacy was the first to propose the identification of this with Sepharad, and subsequently it was suggested by Lassen ( Zeitschr. F. Morged. 5, 1, 50) that S Pa Ra D was identical with Sardis, the ancient capital of Lydia. This identification is approved of by Winer, and adopted by Dr. Pusey ( Introd. To Obadiah p. 232, note, also p. 245). In support of this, F Ü rst (Handwb. 2, 95 a) points out that Antigonus (B.C. cir. 320) may very probably have taken some of his Jewish captives to Sardis; but it is more consistent with the apparent date of Obadiah's prophecy to believe that he is referring to the event mentioned by Joel ( Joel 3:6), when "children of Judah and Jerusalem" were sold to the "sons of the Javanim" (Ionians), which as the first captivity that had befallen the kingdom of Judah, and a transportation to a strange land, and that beyond the sea could hardly fail to make an enduring impression on the nation.

6. Ewald ( Propheten, 1, 404) considers that Sepharad has a connection with Zarephath in the preceding verse; and while deprecating the "penetration" of those who have discovered the name in a cuneiform inscription, suggests that the true reading is Sepharam, and that it is to be found in a place three hours from Akka, i.e. doubtless the modern Shefa Omar, a place of much ancient repute and veneration among the Jews of Palestine (see Zunz, note to Parchi, p. 428); but it is not obvious how a residence within the Holy Land can have been spoken of as a captivity, and there are considerable differences in the forms of the two names.

7. Michaelis ( Suppl. No. 1778) has devoted some space to this name; and, among other conjectures, ingeniously suggests that the "Spartans" (q.v.) of  1 Maccabees 12:15 are accurately "Sepharadites." This suggestion, however, does not appear to have stood the test of later investigations. But it is adopted by Keil (ad loc.), who objects to the view expressed above (No. 5) that Sardis would naturally be Hebraized סורד .

8. Juynboll proposes ( Hist. Samar. p. 20) to read בְּסו פְּרָת , At The End Of (i.e. beyond) The Euphrates, as the origin of the Sept. rendering, but such a phrase would be unnatural.

International Standard Bible Encyclopedia [9]

sḗ - fā´rad , sef´a - rad ( ספרד , ṣephārādh ): Mentioned in   Obadiah 1:20 as the place of captivity of certain "captives of Jerusalem," but no clear indication is given of locality. Many conjectures have been made. The Targum of Jonathan identifies with Spain; hence, the Spanish Jews are called Sephardim. Others (Pusey, etc.) have connected it with the "(Tsparda" of the Behistun Inscription, and some have even identified it with "Sardis." The now generally accepted view is that which connects it with the "Saparda" of the Assyrian inscriptions, though whether this is to be located to the East of Assyria or in Northern Asia Minor is not clear. See Schrader, Cuneiform Inscriptions , II, 145-46; Sayce, HCM , 482-84; articles in DB , HDB , EB , etc.

Kitto's Popular Cyclopedia of Biblial Literature [10]

Seph´arad, a region to which the exiles from Jerusalem were taken . It appears to have been a district of Asia Minor, or at least near to it.