John Calvin Commentary Deuteronomy 28:26

"And thy dead body shall be food unto all birds of the heavens, and unto the beasts of the earth; and there shall be none to frighten them away." — Deuteronomy 28:26 (ASV)

And your carcass shall be meat. The punishment is here doubled by the disgrace that is added to death, for it is shameful to be deprived of burial and is justly counted among the curses of God. While it is a sign of His paternal favor that we should be distinguished from the animals, because the rites of burial awaken us to the hope of resurrection and everlasting life. Therefore, on the contrary, God deprives of burial those whom He curses.

But as we have said that punishments affecting the body are common to the pious and the reprobate, so also we must consider being deprived of burial, since it sometimes happens that the reprobate are honorably buried, as Christ relates of the rich man (Luke 16:22), while the bodies of the pious are shamefully cast out as prey for birds and beasts, as the Prophet complains in Psalm 79:2. Still, such an interchange does not prevent God from avenging the contempt of His Law by this method of punishment, just as He does by pestilence, famine, or sword.