“until water was poured on them from heaven.” That is, until the autumn rains came. The barley harvest started in April, often mid-April, and the autumn rains started in late October or early November, and it was getting colder by then too. So Rizpah watched over her dead sons for at least six months. Some scholars believe that the famine was due to no rain and that therefore the rain that came was not the regular autumn rain but was special and ended the famine, but there is no indication of that in the text. There are lots of times famines occur for other reasons than there being no rain. According to the Mosaic Law (Deut. 21:27), dead bodies should be taken down from being impaled before nightfall. It seems these bodies were left on the stake, but we have no explanation as to why.
“the birds of the air.” The Hebrew is literally, “the birds of the heavens,” but the Hebrew word “heavens” is always plural, there is no singular word “heaven” in Hebrew.
“or the animals of the field by night.” Rizpah kept her vigil day and night, napping on the sackcloth on the rock, and thus she protected the bodies and bones of her beloved sons. This is one of the most profound acts of a mother’s love in the Bible. Eventually the men’s flesh would decay and mostly waste away, leaving the bones. In the biblical culture it was very important to protect and properly bury the bones of the deceased, and Rizpah no doubt wanted to see her sons get a proper burial. She had to keep vigil over the bones, which would have been taken by animals if not guarded. Her diligence and love paid off and eventually her sons got an honorable burial.