People who forget the prayer or sleep through it

Masruq said: The Prophet (peace and blessings be upon him) was on a journey. He halted in the last part of the night, and sleep so overcame them that it was the rays of the sun that woke them. He ordered the mu'adhdhin to call the adhan; he called the adhan, then the iqamah, and he led the prayer. Masruq said: The prayer of the Prophet (peace and blessings be upon him) after sunrise was so dear to us that everything in the world seemed worthless beside it.

Something similar is also reported from Sayyiduna Ibn Abbas (may Allah be pleased with them both).

Ata bin Yasar said that the Prophet (peace and blessings be upon him) prayed the two sunnah rak'ahs of Fajr after crossing the valley. Then he ordered Sayyiduna Bilal (may Allah be pleased with him); he called the adhan and the iqamah, and then he prayed the obligatory prayer.

Al-Hasan said: A man may make up several missed prayers with a single iqamah.

Sayyiduna Abdullah (may Allah be pleased with him) said: One night we travelled with the Prophet (peace and blessings be upon him). At one place we said: O Messenger of Allah, if we halt for a while, we will sleep a little and our mounts will graze. So the Prophet (peace and blessings be upon him) said: "Who will keep watch for us?" I said: I will keep watch. But sleep overcame me, and we woke up only when the sun had already risen. The Prophet (peace and blessings be upon him) also woke up because of our talking. The Prophet (peace and blessings be upon him) ordered Sayyiduna Bilal (may Allah be pleased with him); he called the adhan and the iqamah, and the Prophet (peace and blessings be upon him) led the prayer.