Praise be to Allah, and may Allah’s peace and blessings be upon the Messenger of Allah, his family and his companions.
As to what follows:
You should strive in advising him and waking him up for prayer, if you cannot then nothing is on you. You should also advise him to take necessary measures that will enable him to wake up early from sleep and resolve to go and pray as well as understand the virtues of safeguarding congregational prayer and the rewards that will come from that. However, arousal of his desires and his need to satisfy them during prayer time is part of acceptable excuses that make it permissible for him to absent himself from congregational prayer. This is according to The Prophet’s (peace be on him) saying: “Prayer should not be offered in presence of meals (before the worshipper), or when one is prompted by the call of nature.” [Narrated by Muslim on the authority of Aisha (may Allah be pleased with her)]. This falls under the meaning of what was mentioned by The Prophet (peace be on him) concerning the heart being occupied and not being free. The Prophet (peace be on him) forbade people to perform prayer under these two conditions because it involves the heart being occupied and not being able to devote oneself to prayer as well as leading to hastiness in order to finish quickly. Abu Dar Da’ said: “verily, part of a man’s knowledge is that he should start by fulfilling of his needs then proceed to prayer when his heart is unoccupied”.
And Allah knows best.
Your brother,
Dr. Khalid al-Muslih
11 / 11 / 1424 AH