From BiblePortal Wikipedia

Fausset's Bible Dictionary [1]

A town of Mesopotamia. Balaam's abode ( Numbers 22:5;  Deuteronomy 23:4). Head quarters of the Magi, who congregated in particular spots (Strabo 16:1). From Paathar "to open" or "reveal." Phathusae (Zosim. 3:14), S. of Circesium, and Bethauna (Ptolemy, 5:18, section 6), corruptions of Pethor, answer to Ahab, meaning the same in Arabic (Anatha, Ammian. Marcell. 24:1, 6); on an island in the river Euphrates, and partly also extending both sides of the river; for ages the seat of an ancient pagan worship; a good center for influencing the Arabs on the E. and the Aramaic tribes W. of the river.

Hastings' Dictionary of the Bible [2]

PETHOR. Mentioned in   Numbers 22:5 and   Deuteronomy 23:4 as the home of Balaam, in N. Mesopotamia, when he was called by Balak to curse Israel. With this indication agrees the repeated statement by king Shalmaneser ii. of Assyria regarding a certain city which he calls Pitru , that it lay on the river Sâgûr (modern Sâjûr ), near its junction with the Euphrates. Thus Pethor would seem to have lain a little south of Carchemish, on the west of the Euphrates.

J. F. M‘Curdy.

Smith's Bible Dictionary [3]

Pe'thor. (Soothsayer). A town of Mesopotamia, where Balaam resided, and situated "upon the river," possibly the Euphrates.  Numbers 22:5;  Deuteronomy 23:4. Its position is wholly unknown.

Watson's Biblical & Theological Dictionary [4]

a city of Mesopotamia, of which the Prophet Balaam was a native. The Hebrews call this city Pethura. Ptolemy calls it Pachora; and Eusebius, Pathara. He places it in the Upper Mesopotamia.

Morrish Bible Dictionary [5]

Dwelling place of Balaam in Mesopotamia.  Numbers 22:5;  Deuteronomy 23:4 . Not identified.

Hawker's Poor Man's Concordance And Dictionary [6]

The city of Baalam. ( Numbers 22:5)

Holman Bible Dictionary [7]

 Numbers 22:5 Deuteronomy 23:4

Easton's Bible Dictionary [8]

 Numbers 22:5Balaam

International Standard Bible Encyclopedia [9]

pē´thor ( פּתור , pethōr  ; Φαθοῦρα , Phathoúra , Βαθοῦρα , Bathoúra ): The dwelling-place of Balaam, situated on "the river" (the Euphrates) (  Numbers 22:5 ).

1. Possibly the Asyrian Pitru:

In  Deuteronomy 23:4 , it is further described as being in Mesopotamia ( Aram - naharaim ). Pethor is identified with the Pedru(i) of the geographical lists of Thothmes Iii (circa 1500 BC) and the Pitru (Pithru) of the Assyrian king Shalmaneser II, who states that in his 3rd year (857 BC) he took the city Ana - Aššur - utı̂r - aṣbat (meaning: "I founded (it) anew for Aššur "), which the H̬attâa (Hittites) called Pitru. He says that it lay on the farther (western) bank of the Euphrates, by the Sagūrru or Sagura River, the modern Sajūr . The importance of Pitru is indicated by the fact that he received there the tribute of the kings of Carchemish, Comagene, Melitene and other districts.

2. Difficulties of Identification:

As Pitru is about 400 miles from Moab, this meant for Balaam a three or four weeks' journey, but the messengers sent to fetch him, though they had to travel that distance twice, could naturally, by pressing their mounts, have performed it much less time. Doubt may likewise be entertained as to the identity of Pethor with Pitru by the absence in the latter of the ô , which would lead one to expect rather the Assyrian form Pit ( h ) ūru . Shalmaneser, however, says that Pitru was the Hittite name, and that may account for it. With regard to the derivation, nothing can at present be said, except that, as a Hittite name, Tomkins ( Records of the Past , 5 (London, 1891), 38) has compared the name Pitru with the Pteria of Herodotus i. 76 (identified with Bog - haz - keui , the great Hittite capital in Cappadocia, in ancient times called H̬attu ).

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [10]

(Heb. Pethor', פַּתוֹר , Opened; Sept. ( Φαθουρά ; but in  Deuteronomy 23:6 Sept. omits), the name of a place in Mesopotamia, on the Euphrates, the native country of Balaam, to which Balak sent for him to come and curse Israel ( Numbers 22:5;  Deuteronomy 23:5). It is supposed to have been near Tiphsah, on the Euphrates, but this is altogether uncertain. (See Balaam). The name occurs in the cuneiform inscriptions (q.v.).