From BiblePortal Wikipedia

Hastings' Dictionary of the Bible [1]

JAHAZ (in   1 Chronicles 6:78 ,   Jeremiah 48:21 Jahzah ). A town at which Sihon was defeated by Israel (  Numbers 21:23 ,   Deuteronomy 2:32 ,   Judges 11:20 ). After the crossing of the Arnon, messengers were sent to Sihon from the ‘wilderness of Kedemoth’ (  Deuteronomy 2:26 ), and he ‘went out against Israel into the wilderness and came to Jahaz’ (  Numbers 21:23 ). Jahaz is mentioned in connexion with Kedemoth (  Joshua 13:18;   Joshua 21:36 ). These passages indicate a position for Jahaz in the S. E. portion of Sihon’s territory. Jahaz was one of the Levite cities of Reuben belonging to the children of Merari (  Joshua 13:18;   Joshua 21:36 (see note in RVm [Note: Revised Version margin.] ],   1 Chronicles 6:78 ). According to the Moabite Stone (11:18 20), the king of Israel dwelt at Jahaz while at war with king Mesha, but was driven out, and the town was taken and added to Moabite territory. Isaiah (  Isaiah 15:4 ) and Jeremiah (  Jeremiah 48:21;   Jeremiah 48:34 ) refer to it as in the possession of Moab. The site has not yet been identified.

Fausset's Bible Dictionary [2]

JAHAZA ( Joshua 13:18), Jahazah ( Joshua 21:36), JAHZAH ( Numbers 21:23;  Deuteronomy 2:32;  Judges 11:20;  Isaiah 15:4;  Jeremiah 48:21;  Jeremiah 48:34). Here the battle was fought wherein Israel overcame Sibon and so won his whole territory between the Arnon and the Jabbok. Jahaza was assigned to Reuben, then to the Merarite Levites ( 1 Chronicles 6:78;  Joshua 21:36). It was in the plain country, now the Belka , in the extreme S. of Sihon's land but N. of the Arnon. Doubtless the battle was fought along the slope of the hill still called Shihan . There is on it a network of cyclopean walls, whence the slings and arrows of Israel dislodged the Amorites according to Josephus. Thence the enemy fled two miles to the edge of the Arnon gorge.

People's Dictionary of the Bible [3]

Jahaz ( Jâ'Hâz ), Place Trodden Down. A Moabitish city situated near the desert; afterward reckoned to the tribe of Reuben and assigned to the priests.  Numbers 21:23;  Deuteronomy 2:32;  Isaiah 15:4;  Jeremiah 48:34. It is also called Jahaza,  Joshua 13:18, A. V. Jahazah,  Joshua 21:36;  Jeremiah 48:21, A. V., and Jahzah.  1 Chronicles 6:78 A. V., and  Jeremiah 48:21 R. V. At this place the Israelites gained a victory over Sihon and conquered the territory between the Arnon and the Jabbok; but in later times Jahaz seems to have been occupied by the Moabites.

Smith's Bible Dictionary [4]

Ja'haz. (Trodden Down). Under these four forms (Jahaz , Jahaza , Jahazah and Juhzah ) is given, in the Authorized Version, the name of a place which in the Hebrew appears as Yahats and Yahtsah .

At Jahaz, the decisive battle was fought between the children of Israel and Sihon, king of the Amorites.  Numbers 21:23;  Deuteronomy 2:32;  Judges 11:20. It was in the allotment of Reuben.  Joshua 13:18. Like many others relating to the places east of the Dead Sea, the question of its site must await further research.

Holman Bible Dictionary [5]

 Numbers 21:23-24 Deuteronomy 2:32-33 Judges 11:20-21 Isaiah 15:4 Jeremiah 48:34 Jeremiah 48:21 ah   Joshua 13:18 Joshua 21:36 1 Chronicles 6:78

Easton's Bible Dictionary [6]

 Joshua 13:18 1 Chronicles 6:78 Numbers 21:23 Deuteronomy 2:32 Joshua 13:18 21:36 Isaiah 15:4 Jeremiah 48:34

American Tract Society Bible Dictionary [7]

JAHAZAH or JAHZAH, a city in the north of Moab, near which Moses defeated Sihon,  Numbers 21:23 . It was in the limits of Reuben, and was a Levitical city,  Joshua 21:36 . In  Isaiah 15:4 , and  Jeremiah 48:21 , it appears as again in the hands of the Moabites.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [8]

(Heb. Yat'hats, יִהִוֹ , Trodden down,  Isaiah 15:4;  Jeremiah 48:34; Sept. Ι᾿Ασσά ; also with ה local and in pause, י הְצָה , Yach'Tsah,  Numbers 21:23, Sept. Εἰς Ι᾿Ασσά ;  Deuteronomy 2:32, Sept. Εἰς Ι᾿Ασά ; and this even with a prefix, בְּי הְצָה ,  Judges 11:20, Sept. Εἰς Ι᾿Ασσά ; but likewise with ה paragogic, יִהְצָה , Yah'Tsach, Sept. Ι᾿Ασσά ,  Joshua 13:18; A. Vers. "Jahaza;" Ι᾿Ασά ,  Jeremiah 48:21, "Jahazah;" Ι᾿Ασσά ,  Joshua 21:36, "Jahazah;" ῾Ρεφάς v.r. Ι᾿Ασσά , 2 Chronicles 6:78, "Jahzah"), a town beyond the Jordan, where Sihon was defeated, in the borders of Moab and the region of the Ammonites ( Numbers 21:23;  Deuteronomy 2:32;  Judges 11:20); situated in the tribe of Reuben ( Joshua 13:18), and assigned to the Merarite Levites ( Joshua 21:36;  1 Chronicles 6:78). In  Isaiah 15:4;  Jeremiah 48:21, it appears as one of the Moabitish places that suffered from the transit of the Babylonian conquerors through the "plain country' (i.e. the Mishor. the mod. Belka). The whole country east of the Dead Sea had originally been given to the Moabites and Ammonites ( Genesis 19:36-38;  Deuteronomy 2:19-22); but the warlike Amorites from the west of the Jordan conquered them, and expelled them from the region north of the river Amon. From the Amorites the Israelites took this country, but subsequently the Ammonites claimed it as theirs ( Judges 11:13), and on the decline of Jewish power the Moabites and Ammonites again took possession of it. Hitzig (Zu Jesa. ad loc.) regards Jahaz and Jahzah as different places (so Keil on Joshua ad loc., urging that they are distinguished in the passages of Jeremiah); but this is unnecessary (so Winer, Real. s.v. Jahaz), and at variance with the philology. It appears to have been situated on the- edge of the desert (see Raumer, Zug dc. Isr. p. 53; Hengstenberg, Bileame, p. 239). See Exodus. From the terms of the narrative in Numbers 21 and Deuteronomy 2 we should expect that Jahaz was in the extreme south part of the territory of Sihon, but yet north of the River Arnon (see  Deuteronomy 2:24;  Deuteronomy 2:36; and the words in  Deuteronomy 2:31, "begin to possess"), and in exactly this position a site named Jazaze is mentioned by Schwarz (Palest. p. 227, "a village to the south-west of Dhiban"); but this lacks confirmation, especially as Eusebius and Jerome (Ozomnasf s. Ι᾿Εσσά , Jassa) place it between Medeba ( Μηδαμών ) and Dibon ( Διβούς ,'Deblathaim); and the latter states that "Jahaz lies opposite the Dead Sea, at the boundary of the region of Moab." These requirements are met by supposing Jahaz to have been situated in the open tract at the head of wady Waleh, between Arnun on the east, and Jebel Humeh on the west.

International Standard Bible Encyclopedia [9]

jā´haz ( יהץ , yahac ,   Isaiah 16:4;  Jeremiah 48:34 , יהצה , yahăcāh , or יהצה , yahcāh ,  Numbers 21:23;  Deuteronomy 2:32;  Joshua 13:18;  Joshua 21:36 , the King James Version "Jahazah";  Judges 11:20;  Jeremiah 48:21;  1 Chronicles 6:78 , "Jahzah"): This is the place where in a great battle Israel overwhelmed Sihon king of the Amorites, and then took possession of all his territory ( Numbers 21:23 , etc.). It is named along with Beth-baal-meon and Kedemoth ( Joshua 13:18 ), with Kedemoth ( Joshua 21:37 ) pointing to a position in the Southeast of the Amorite territory. It was given to Reuben by Moses, and was one of the cities in the portion of that tribe assigned to the Merarite Levites. Mesha (MS, ll. 18 if) says that the king of Israel dwelt in Jahaz when at war with him. Mesha drove him out, and the city passed into the hands of Moab. It is referred to as a city of Moab in  Isaiah 15:4;  Jeremiah 48:21 ,  Jeremiah 48:34 . Cheyne thinks that either Jahaz or Kedemoth must be represented today by the important ruins of Umm er - Reṣāṣ , about 2 1/2 hours North of Dibon toward the desert ( EB , under the word). No certain identification is possible.