Was the Prophet (peace be upon him) an ascetic, and what are the proofs of that from the Qur'an and Sunnah?

The Prophet, peace and blessings be upon him, was the most ascetic of people concerning worldly matters. He would give away in charity all the wealth that came to him and would ask Allah to grant him only what was sufficient. Among the manifestations of his asceticism were:

He never ate his fill of wheat bread for three consecutive days until his death. Two months would pass without a fire being lit in the homes of his wives; their food was dates and water. He passed away with nothing in his house for anyone with a liver to eat except half a measure of barley. He would spend successive nights hungry, and his family would not find dinner. He would tie a stone to his stomach due to hunger. Upon his death, he left behind nothing but his weapon, his mule, and land which he had given away in charity. He used to sleep on a mat until it left marks on his side. He likened himself in this world to a rider who seeks shade under a tree, then departs and leaves it behind.