The Obligation Of The Muslims Towards The Kuffaar (disbelievers) Whom Islaam Has Not Reached
There are Shuroot ‘Aammah (general conditions) for At-Takleef in which there is no difference between the Muslim and Kaafir in respect to them and these conditions are: Al-Buloogh (maturity i.e. past the age of puberty), Al-‘Aql (sound mind) and Al-Qudrah (capability).
The evidence for that is the Qawl of the Messenger (saw):
The pen has been lifted from three: The sleeping person until he awakens, the boy until he reaches the age of puberty and the one who has lost his mind until he can rationally reason/understand again (Abu Daawood).
The meaning of the pen being lifted is that the Takleef (legal responsibility) has been lifted. Also Allah Ta’Aalaa does not burden or task a person unless he was capable and qualified (or competent) for the Takleef. That is due to the Qawl of Allah (swt):
Allah does not charge a soul except [with that within] its capacity (Al-Baqarah 286).
In respect to the Buloogh or when someone is Baaligh then this refers to the age of maturity (Sin Ar-Rushd) which for a man is at the time of Ihtilaam which refers to the emission of Al-Maniy (seminal discharge). When Sa’d Ibn Mu’aadh (ra) passed judgment of death upon the men of Bani Quraizhah, the Baaligh (the mature one i.e. classified as man) was identified by the growth of pubic hair. That is whilst the maturity of the woman is ascertained by the start of her menstruation.
Additionally, the person is only legally responsible (Mukallaf) if he has a sound mind (‘Aaqil) and that is because the ‘Aql represents the Manaat At-Takleef (the place upon which the Takleef rests) and it is the mind that has been addressed by the Ahkaam because the ‘Aql represents the aware, cognisant and comprehending power within the human being and without the mind the human would become like the animal and unable to understand the address or speech that has been directed to him.