Hanging traitors is humane.
And if a man have committed a sin worthy of death, and he be to be put to death, and thou hang him on a tree:
His body shall not remain all night upon the tree, but thou shalt in any wise bury him that day; (for he that is hanged is accursed of God;) that thy land be not defiled, which the Lord thy God giveth thee for an inheritance.
Deuteronomy 21:22-23