Who said, "I have warned him who has been excused," and why and to whom was it said?

This is a common, ancient, and eloquent proverb. It means that whoever warns and cautions leaves no excuse for the one being warned. Related to this meaning is the saying of the Prophet, peace and blessings be upon him: "Allah has removed all excuses from a person whose life He extends until he reaches the age of sixty" (narrated by Al-Bukhari). This means that Allah has been exceedingly fair and just with him.