Sunan Abi Dawud Book 5, Hadith 61
When one of you dozes in prayer he should sleep till his sleep is gone, for when one of you prays while he is dozing, perhaps he might curse himself if he begs pardon of Allah.
The Prophet (ﷺ) said: If a man awakens his wife at night, and then both pray or both offer two rak'ahs together, the (name of the )man will be recorded among those who mention the name of Allah, and the (name of the) woman will be recorded among those who mention the name of Allah. Ibn Kathir did not narrate this tradition as a statement of the Prophet (ﷺ), but he reported it as a statement of Abu Sa'id.
Abu Dawud said: This tradition has been narrated by Ibn Mahdi from Sufyan and I think he mentioned the name of Sufyan. He also said: The tradition transmitted by Sufyan is a statement of the Companion (and not that of the Prophet).
The Messenger of Allah (ﷺ) as saying: When one of you gets up by night (to pray), and falters in reciting the Qur'an (due to sleep), and he does not understand what he utters, he should sleep.