It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that a mentally afflicted woman who had committed fornication was brought to Sayyiduna Umar (may Allah be pleased with him), and he ordered that she be stoned. Meanwhile Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) passed by, while children were following behind the woman. He asked: What is this matter? The people said that Umar (may Allah be pleased with him) had ordered that she be stoned. The narrator said: So he took her back, went with her to Sayyiduna Umar (may Allah be pleased with him) and said: Do you not know that the pen has been lifted from three kinds of people? (They are): the insane until he regains his reason, the (mentally) afflicted until he recovers, the sleeper until he wakes up, and the child until he reaches puberty. This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it.