In Genesis 3, when God cursed the ground on account of Adam, he assured Adam — and all those to be born of Adam — that under this new order of affairs which man had brought upon the world, his efforts to feed himself and his family would for the foreseeable future be accompanied by pain and sweat.
Naturally, being what he is, fallen man has spent the better part of the next six millennia trying to find ways to do an end-around God’s edict.