What are the signs of reaching puberty (Bulugh) for a male?

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Puberty is attained through one of three conditions. The first is seminal emission (ihtilam), which is the discharge of semen from the male organ or the female private part, whether awake or asleep. This is undisputed. Evidence is found in the verses of the Quran commanding those who have not reached puberty to seek permission three times (Quran 24:58-59). Additionally, the Prophet, peace and blessings be upon him, stated, "There is no completion after wet dreams [ihtilam]" and commanded Mu'adh, "Take one Dinar from every male who has had a wet dream." The second sign is the growth of coarse hair around the private parts. Evidence for this is the narration of Atiyyah al-Quradhi, stating that those among the Bani Qurayza who had not grown hair were spared execution, while those who had grown it were killed. This hadith is classified as Hassan Sahih. Furthermore, Umar used to instruct the commanders of the armies not to kill anyone except those upon whom the razors had passed (i.e., grown pubic hair) and not to collect the Jizyah except from those upon whom the razors had passed.