Is reaching fifteen years of age a sign of male puberty?

Primary text

The third sign of male puberty is reaching fifteen years of age. This is evidenced by the narration of Ibn Umar, who stated that he was presented before the Prophet, peace and blessings be upon him, at the age of fourteen and was not permitted to fight, but when presented at fifteen, he was permitted to fight. Nafi' reported that when this hadith was related to Umar bin Abd al-Aziz, he stated, "This is the demarcation between men and boys," which is agreed upon.