# bury him the same day

"bury him on the same day as when you execute him". See John 19:31 and Galatians 3:13.

# for whoever is hanged is cursed by God

"because God curses everyone whom people hang on trees" and "for people hang on trees those whom God has cursed." 

# You must not defile the land

Leaving the body on the tree would defile the land.