—namely, an age that a person would not ordinarily reach unless he had already experienced a seminal emission. At that point the ḥadd is carried out if he commits an act for which the ḥadd is prescribed.
Aṣbagh ibn al-Faraj said: Ibn al-Qāsim informed me, saying, “I heard Mālik declare: ‘Our practice is based on the report from ʿUmar ibn al-Khaṭṭāb: “Had the razors passed over him, I would have carried out the ḥadd on him.”’” Aṣbagh continued: “Ibn al-Qāsim also said to me, ‘My preference is that the ḥadd not be enforced unless both pubic hair has appeared and full maturity is established.’” Aṣbagh added: “Our own position is that the age of puberty at which the obligations become binding is fifteen lunar years. That is the view I prefer and deem best, because at that age a person receives a share of the spoils when present in battle. He supported this with the ḥadith of Ibn ʿUmar: he was presented [for service] on the Day of the Trench at fifteen years of age and was accepted, whereas he had not been accepted at Uḥud because he was fourteen.”
Abū ʿUmar said: “This ruling concerns one whose date of birth is known. As for a person whose birthdate is unknown and who has neither experienced a seminal emission nor admits to it, the ruling follows what Nāfiʿ narrated from Aslam, from ʿUmar ibn al-Khaṭṭāb—may Allah be pleased with him—that he wrote to the army commanders: ‘Do not impose the jizya on anyone until the razors have passed over him.’”
ʿUthmān said regarding a lad who had stolen: “Examine him; if the waistband of his lower garment has turned green—meaning he has grown pubic hair—then cut off his hand.”
ʿAṭiyya al-Qurazī reported: “The Messenger of Allah ﷺ inspected the Banū Qurayẓa; everyone who had grown pubic hair was executed in accordance with the judgment of Saʿd ibn Muʿādh, while those who had not were spared. I was among those who had not…"