Shaykh al-Islām—may Allah have mercy on him—was asked about a man who does not come to rest in his prayer.

He replied:

Coming to rest in prayer is obligatory, and all the imams agree that whoever omits it is at fault. Indeed, the majority of the imams of Islam—such as Mālik, al-Shāfi‘ī, Ahmad, Ishāq, and Abū Yūsuf, the associate of Abū Hanīfah—as well as Abū Hanīfah and Muhammad, do not dispute that whoever omits this is acting wrongly and not performing the prayer properly. Rather, he is sinning, disobeying, and neglecting an obligation. Others require anyone who omits coming to rest to repeat the prayer.

The evidence that repeating it is obligatory is the report in the two Sahīh collections:

“A man prayed two units of prayer in the mosque, then came and greeted the Prophet, may Allah bless him and grant him peace. The Prophet, may Allah bless him and grant him peace, told him two or three times: ‘Go back and pray, for you have not prayed.’

“The man said: ‘By Him who sent you with the truth, I do not know how to do any better than this. Teach me what will suffice for my prayer.’

“He said: ‘When you stand for prayer, proclaim Allah’s greatness, then recite whatever you can of the Quran. Then bow until you come to rest in bowing. Then rise until you are standing upright. Then prostrate until you come to rest in prostration. Then sit until you come to rest in sitting. Do this throughout your prayer.’”

This man was ignorant, yet the Prophet commanded him