Then the Philistine said to David, “Come to me, and I will give your flesh to the birds of the air and to the animals of the field.” Bible

“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.

“and to the animals of the field.” There would be no proper burial. This was a threat of death with dishonor.

Commentary for: 1 Samuel 17:44