Deuteronomy 2:19

And when thou comest nigh over against the children of Ammon, distress them not, nor meddle with them: for I will not give thee of the land of the children of Ammon any possession; because I have given it unto the children of Lot for a possession.

When thou comest nigh over against the children of Ammon. The Ammonites, being kindred to the Moabites, were, from regard to the memory of their common ancestor, to remain undisturbed by the Israelites. The two people are mentioned as brother tribes, "the children of Lot" (cf. 2 Chronicles 20:1; Zephaniah 2:8). The territory of this people had been directly north of that of Moab, and extended as far as the Jabbok, having been taken by them from a number of small Canaanite tribes-namely, the Zamzummins, a bullying, presumptuous band of Rephaim (see the note at Deuteronomy 2:11). The etymology of this name is not known, though many conjectures are made. Gesenius considers it to mean 'noisy people,' from zimzam, 'to make a noise.' Ewald and others view it as a compound of Zuwziym (H2104) 'eeymiym (H368), 'the terrible Zuzim:' see the note at Genesis 14:5.)