Q: I am a 13 year old boy. I am not baaligh (mature) because my voice has not cracked but when I masturbate sperm comes out. Am I getting sina for masturbating because I am not baaligh?
A: Maturity in a boy means that when he starts experiencing wet dreams and in a girl when she experiences her first period (Haidh).
If these signs of maturity do not become apparent and the child has already reached the age of fifteen Islamic years, the child will be considered to be mature. If these signs become apparent before the age of fifteen, the child will be considered to be mature (Baaligh) from the time the sign became apparent. Remember that these years will be counted according to the Islamic calendar.
In your case it is not wet dreams but masturbation. The fact that you are releasing sperm is a clear sign that you are now Baaligh. It is not necessary for the voice to crack to be Baaligh. Now all the laws of Islam apply to you. So the sin of masturbation will also apply.
Stop this now, for, if you carry on and you become addicted to it, it will be more difficult to leave it later. There are great promises in the Hadeeth for a youth who protects himself.
Sayyidina Ataa' was asked regarding this. He said that a group of people will be resurrected on Qiyaamah and their hands will be pregnant. It will be these people who had been doing this and did not repent. Their fault will be witnessed by everyone on Qiyaamah.
Sayyidina Sa'eed ibni Jubayr says that Allah will punish those people who play with their private parts.
This applies to both males and females.
A person, who excessively commits this act, will not be physically fit for marriage in later life, eyes and memory becomes weak, etc.
Ghusl is necessary after masturbation.
May Allah Ta'aala protect you, Aameen.
Moulana Yusuf Laher