Syedna Ali (may Allah be pleased with him) once said to Syedna Umar (may Allah be pleased with him): O Commander of the Faithful! Have you not heard that the Messenger of Allah (peace and blessings be upon him) said: "Three types of people are exempt from accountability: (1) The sleeping person until he wakes up, (2) The child until he reaches puberty, (3) The insane person until his sanity returns."