Should a person be woken for Fajr prayer if it is certain that they will not wake up to pray it?

Scholars differ on the ruling of waking a sleeper for prayer, holding two opinions: it is recommended, and it is obligatory (which is the view of the Hanbalis). According to the opinion of obligation, it is obligatory to wake him, even if his waking is not expected. However, some Hanbalis believe it is not obligatory in this case if it is known that waking him will be of no benefit, and this is based on the premise that enjoining good is not obligatory unless compliance from the one being enjoined is expected. Nevertheless, the [Hanbali] madhhab obligates waking him whether it benefits or not, based on the Almighty's saying: {and enjoin good}. The safer course of action is to wake him to absolve oneself and to exit the difference of opinion.