The hadeeth about the man who prayed badly was narrated by al-Bukhaari (757) and Muslim (397) from Abu Hurayrah (may Allaah be pleased with him), that the Messenger of Allaah (peace and blessings of Allaah be upon him) entered the mosque and a man came in and prayed, then he came and greeted the Messenger of Allaah (peace and blessings of Allaah be upon him). The Messenger of Allaah (peace and blessings of Allaah be upon him) returned the greeting and said: “Go back and pray, for you have not prayed.” The man went back and prayed as he had prayed before, then he came to the Prophet (peace and blessings of Allaah be upon him) and greeted him, and the Messenger of Allaah (peace and blessings of Allaah be upon him) said, “Wa ‘alayk al-salaam.” Then he said: “Go back and pray, for you have not prayed.” When he had done that three times, the man said: By the One Who sent you with the truth, I cannot do more than that. Teach me. He said: “When you go to pray, say takbeer, then recite whatever you can of the Qur’aan. Then bow until you are at ease in bowing, then rise until you are standing up straight. Then prostrate until you are at ease in prostration, then sit up until you are at ease in sitting. Then do that throughout the entire prayer.”
Both ahaadeeth indicate that the one who is ignorant is excused, but in the hadeeth of Mu’aawiyah he is not commanded to repeat the prayer, whereas in the hadeeth of the one who prayed badly, he is not commanded to repeat the prayers he had offered before, rather he was commanded to repeat the current prayer only.
Al-Nawawi (may Allaah have mercy on him) said, commenting on the hadeeth of Mu’aawiyah: As for the words of the ignorant one, it was because he was new in Islam, so they are like the words of one who forgets, so they did not invalidate his prayer if they were few, because of this hadeeth of Mu’aawiyah ibn al-Hakam, which we are discussing here, because the Prophet (peace and blessings of Allaah be upon him) did not command him to repeat the prayer. But he taught him that it is haraam to talk during prayers for future reference. End quote.
With regard to commanding the one who prayed badly to repeat his prayer when he did not command Mu’aawiyah to do so, that is because there is a difference between doing that which is forbidden and not doing that which is enjoined. Omitting what is enjoined is not excused because of ignorance or forgetfulness when it is possible to make it up, which is unlike doing what is forbidden.
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said, in a discussion of things that are forbidden whilst in ihraam: The correct view is that all of them may be excused. If a person is excused due to ignorance, forgetting or being forced to do something , there are no consequences to his actions whatsoever, whether it has to do with having intercourse, hunting, clipping the nails, wearing tailored garments or anything else. We have mentioned above evidence from the Qur’aan, Sunnah and rational thought.
The same applies to all other actions that are forbidden during acts of worship; the ruling does not apply, if they happen in cases of ignorance forgetfulness or compulsion, because of the general meaning of the texts and because the penalty, fidyah or kafaarah (expiation) is only prescribed in order to compensate for going against the rules or to expiate sins, but the ignorant, forgetful person or one who is forced did not deliberately go against the rules, and if he had remembered, been aware or had the choice he would not have done it.
If a person drinks by mistake in Ramadaan (because he forgets he is fasting), he does not have to make it up. The evidence for that is the hadeeth of Abu Hurayrah (may Allaah be pleased with him): “Whoever forgets when he is fasting and eats or drinks, let him complete his fast, for it is Allaah Who has fed him and given him to drink.” The one who does not deliberately go against the rule is not sinning and does not have to offer any fidyah.
Similarly, when ‘Adiyy ibn Haatim wanted to fast, he took a black thread and a white thread, because of the verse in which Allaah says (interpretation of the meaning): “and eat and drink until the white thread (light) of dawn appears to you distinct from the black thread (darkness of night), then complete your Sawm (fast) till the nightfall” [al-Baqarah 2:187]. They used to take the rulings directly from the Qur'aan. But the Prophet (peace and blessings of Allaah be upon him) said to him: “Your pillow must be very wide, if the black and white threads are beneath your pillow.” But he did not command him to repeat the fast because he was ignorant of the ruling.
Similarly, Asma’ bint Abi Bakr (may Allaah be pleased with her) said that they broke the fast on a cloudy day at the time of the Messenger of Allaah (peace and blessings of Allaah be upon him), and he did not command them to make it up – because they were unaware of the fact that the sun had not yet set.
The same applies to prayer. The evidence is that Mu’aawiyah ibn al-Hakam (may Allaah be pleased with him) started to pray with the Prophet (peace and blessings of Allaah be upon him) and a man sneezed, so he said, “Yarhamuk-Allaah (may Allaah have mercy on you)” whilst he was praying. The people glared at him – i.e., they looked at him disapprovingly – and he (may Allaah be pleased with him) said, “May my mother be bereft of me!”, i.e., he added more words to what he had said. So they started to slap their thighs with their hands to make him be quiet, and he fell silent. When he had said the salaam, the Messenger (peace and blessings of Allaah be upon him) called him. Mu’aawiyah said: May my father and mother be sacrificed for him; by Allaah I have never seen a better teacher or better teachings before or since; he did not rebuke me, hit me or revile me – he said: “This prayer is not the right place for any of the people’s speech, rather it is tasbeeh, takbeer and recitation of Qur’aan.” And he did not tell him to repeat it because he was unaware of the ruling.
The texts point to this principle, which is not blaming people for forgetting, not knowing, or being forced to do something. This is what is implied by the words of Allaah (interpretation of the meaning):
“your Lord has written (prescribed) Mercy for Himself, so that if any of you does evil in ignorance, and thereafter repents and does righteous good deeds (by obeying Allaah), then surely, He is Oft‑Forgiving, Most Merciful”
And the words of Allaah in the hadeeth qudsi: “My mercy prevails over My wrath.”
Omitting to do that which is enjoined, however, is not excused on the basis of forgetting, ignorance or being forced, when it is possible to make it up, because the Prophet (peace and blessings of Allaah be upon him) said: “Whoever sleeps and misses a prayer or forgets it, let him pray it when he remembers it.” So it is not waved in the case of forgetting. And because the Prophet (peace and blessings of Allaah be upon him) did not waive the current prayer on the grounds of ignorance, as we see in the hadeeth of the one who prayed badly; he commanded him to repeat it even though he was ignorant, because he was omitting to do something enjoined.
Moreover, it is possible to make up things that are enjoined, but forbidden things are over and done with. But if a person is doing something that is forbidden, he should stop doing it as soon as he realizes. If someone says that Allaah’s words (interpretation of the meaning): “Our Lord! Punish us not if we forget or fall into error” [al-Baqarah 2:286] are general in meaning and include both omitting things that are enjoined and doing things that are forbidden, the response is that that is indeed the case; the one who does not do something that is enjoined out of ignorance or because he forgets will not be punished for not doing it, but not doing it means that he is obliged to discharge his duty once the excuse is no longer applicable. End quote from al-Sharh al-Mumti’ (7/200).
And Allaah knows best.