I say, and with God's success: It is not obligatory upon him; because reaching maturity is a condition for its obligation, and he is not among those addressed. Ali (may Allah be pleased with him) said: "The pen is lifted from three: from the child until he reaches maturity, from the sleeper until he wakes up, and from the insane until he recovers," in Sunan Abi Dawood 4: 140, and Sunan al-Nasa'i al-Kubra 4: 324, and Musnad al-Tayalisi 1: 15, and Musnad Abi Ya'la 1: 440. Refer to: Maraqi al-Falah, p. 173, and Allah knows best.