Baligh

In Islamic legal terminology, bāligh ( ar, بالغ, adult) or mukallāf ( ar, مكلف, responsible) or muhallāq ( ar, محلاق, tendril, mentally matured) or murāhiq (, adolescent) or muhtalim ( ar, محتلم, pubescent) refers to someone who has reached maturity or puberty, and has full responsibility under Islamic law.

Quran

The Qur'an refers to puberty in 6:152; 12:22; 17:34; 18:82: 22:5; 28:14; 40:67: 46:15 and 3 times in chapter 24 An-Nisa (31, 58, 59), where reference is made to a prepubescent child's unawareness of sexual matters, which allows him or her to be with an adult whose state of dress would preclude more mature individuals from being present. One includes children who have not reached puberty in a list of those before whom woman may adopt a more relaxed standard of dress than what is normally stipulated in the verse 31 of An-Nur (24:31). The other makes a distinction between children who have reached puberty and those who have not, with the latter having access to parents who might be in a state of undress.

Hadith

Before the age of puberty, a person's faults and crimes are not generally considered as irrevocable according to the hadith. According to another hadith, at starting puberty, the recording angels start recording bad deeds such as missing regular prayers.Prophet of Islam