Commentary for Numbers 21:19

וממתנה נחליאל — Understand this as the Targum does: And after it had been given them, it descended into the valley.

וממתנה נחליאל, in spite of this the waters neither increased nor decreased as a result of their behaving so erratically and having to traverse both depressions in the earth and hilly country.

וממתנה נחליאל, and from Matanah to Nachliel. This well was not like the other wells which supplied a steady amount of water, but it increased as time went on so that it was easily accessible even when the Israelites crossed elevations in the ground on their way.

וממתנה, “and from Matanah;’” they came to Nachaliel, the word being a combination of river and valley. In Numbers 33,48, the Torah refers to this as the Israelites journeying from the chain of mountains known as harey haavarim.” From that point onwards, the Israelites made camp in the wilderness also known as שדה מואב, “the field or fields” of Moav. This was the last place where they made camp before crossing the Jordan river into the Holy Land.

ומנחליאל, “and from Nachaliel;” they spread out from there to bamot, called בית הישימות in Numbers 33,49. The Emorites would refer to places where they worshipped their idols: bamot, “elevated places,” whereas the Israelites called the same sites beyt hayeshimites, “houses of desolation.” Our sages in the Talmud tractate Avodah Zarah, folio 46, go into more detail about all this.