Silsilat al-Ahadith al-Sahihah

Sayyiduna Jabir (may Allah be pleased with him) says: The Messenger of Allah (peace and blessings be upon him) passed by a man who was standing on a rock performing prayer. The Prophet (peace and blessings be upon him) went to one side of Makkah, stayed there for a while, and then returned. He found that man still praying in the same state. The Prophet (peace and blessings be upon him) brought his two hands together and said: "O people! Adopt moderation, for Allah does not tire until you tire."

Sayyiduna Sahl bin Abu Umamah bin Sahl bin Hunaif narrates from his father, and he from his grandfather, that the Prophet Muhammad (peace and blessings be upon him) said: “Do not be harsh upon yourselves in matters of religion, for those before you were destroyed because of their harshness upon themselves. Even now, you can see the remnants of such people in churches and the monasteries of monks.”