The Messenger of Allah (ﷺ) as saying: When one of you gets up by night (to pray), and falters in reciting the Quran (due to sleep), and he does not understand what he utters, he should sleep.
Sunan Abi Dawud Book 5, Hadith 62
← Previous Hadith 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.

Sunan Abi Dawud Book 5, Hadith 61 Next Hadith → The Messenger of Allah (ﷺ) entered the mosque (and saw that) a rope tied between two pillars. He asked: What is this rope (for) ? The people told him: This is (for) Hamnah b. Jahsh who prays (here). When she is tired, she reclines on it. The Messenger of Allah (ﷺ) said: She should pray as much as she has strength. When she is tired, she should sit down.

This version of Ziyad has: He said: What is this ? The people told him: This is for Zainab who prays. When she becomes lazy, or is tired, she holds it. He said: Undo it. One of you should pray in good spirits. When he is lazy or tired, he should sit down.

Sunan Abi Dawud Book 5, Hadith 63