Hadith: Go back and pray, for you have not prayed

عَنْ أَبِي هُرَيْرَةَ رضي الله عنه:
أَنَّ رَسُولَ اللَّهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ دَخَلَ المَسْجِدَ فَدَخَلَ رَجُلٌ، فَصَلَّى، فَسَلَّمَ عَلَى النَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ، فَرَدَّ وَقَالَ: «ارْجِعْ فَصَلِّ، فَإِنَّكَ لَمْ تُصَلِّ»، فَرَجَعَ يُصَلِّي كَمَا صَلَّى، ثُمَّ جَاءَ، فَسَلَّمَ عَلَى النَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ، فَقَالَ: «ارْجِعْ فَصَلِّ، فَإِنَّكَ لَمْ تُصَلِّ» ثَلاَثًا، فَقَالَ: وَالَّذِي بَعَثَكَ بِالحَقِّ مَا أُحْسِنُ غَيْرَهُ، فَعَلِّمْنِي، فَقَالَ: «إِذَا قُمْتَ إِلَى الصَّلاَةِ فَكَبِّرْ، ثُمَّ اقْرَأْ مَا تَيَسَّرَ مَعَكَ مِنَ القُرْآنِ، ثُمَّ ارْكَعْ حَتَّى تَطْمَئِنَّ رَاكِعًا، ثُمَّ ارْفَعْ حَتَّى تَعْدِلَ قَائِمًا، ثُمَّ اسْجُدْ حَتَّى تَطْمَئِنَّ سَاجِدًا، ثُمَّ ارْفَعْ حَتَّى تَطْمَئِنَّ جَالِسًا، وَافْعَلْ ذَلِكَ فِي صَلاَتِكَ كُلِّهَا».
[صحيح] - [متفق عليه] - [صحيح البخاري: 757]

Abu Hurayrah (may Allah be pleased with him) reported:
The Messenger of Allah (may Allah's peace and blessings be upon him) entered the mosque, and then a man came in and prayed. He greeted the Prophet (may Allah's peace and blessings be upon him), who responded and said: "Go back and pray, for you have not prayed." He went back and prayed as he had prayed, then, he came to the Prophet (may Allah's peace and blessings be upon him) and greeted him. He said: "Go back and pray, for you have not prayed," three times. So, he said: By the One Who sent you with the truth, I cannot do better than that. So teach me. He said: "When you stand to pray, say Takbīr (Allāhu Akbar), then recite whatever you can of the Qur’an; 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; and then sit up until you are at ease in sitting. Do that throughout your prayer."
[Authentic hadith] - [Narrated by Bukhari & Muslim] - [Sahih Bukhari - 757]

Explanation

The Prophet (may Allah's peace and blessings be upon him) entered the mosque, and a man entered after him and prayed two quick Rak‘ahs (units of prayer) without being calm in his standing, bowing, and prostration. The Prophet (may Allah's peace and blessings be upon him) was observing him as he prayed. The man then went over to the Prophet (may Allah's peace and blessings be upon him) who was sitting in a corner of the mosque, and greeted him. The Prophet (may Allah's peace and blessings be upon him) returned his greeting and said to him: Go back and repeat your prayer for you have not prayed. He went back and prayed quickly as he did before, then he came and greeted the Prophet (may Allah's peace and blessings be upon him), who said to him: Go back and pray for you have not prayed. He did this three times. The man then said: By the One Who sent you with the truth, I cannot do better than that. So teach me. He (may Allah's peace and blessings be upon him) said to him: When you stand for prayer, say the opening Takbīr, then recite the Opening of the Qur’an (Surat al-Fātihah) and whatever else Allah wills for you to recite. Then bow down until you are at ease in your bowing, placing your palms on your knees and straightening your back, allowing your body to settle into the bowing position. After that, rise up and stand upright until your bones return to their joints and you stand straight. Then prostrate until you are at ease in your prostration, by ensuring that your forehead, nose, palms, knees, and the tips of your toes are on the ground. After that, raise yourself until you are at ease sitting between the two prostrations. Do this in every Rak‘ah of your prayer.

Benefits from the Hadith

1. These pillars of prayer cannot be waived, whether out of forgetfulness or ignorance, as evidenced by the command for the praying person to repeat his prayer. The Prophet (may Allah's peace and blessings be upon him) did not suffice only to teach him.
2. Maintaining composure is one of the pillars of prayer.
3. An-Nawawi said: It indicates that whoever fails to perform any of the obligatory acts of prayer, his prayer is invalid.
4. An-Nawawi said: It also indicates being gentle with the learner and the ignorant, treating them kindly, clarifying the issue for them, summarizing the main objectives, and focusing on what is essential for them rather than the supplementary aspects that they may not be able to memorize or implement.
5. An-Nawawi said: This indicates that if a Mufti is asked about something and there is another matter that the questioner needs but did not inquire about, it is recommended for the Mufti to mention it. This should be considered as advising rather than speaking about irrelevant matters.
6. The merit of admitting negligence is clear in his statement: "I cannot do better than that. So teach me."
7. Ibn Hajar said: It indicates enjoining what is good and forbidding what is evil, as well as the learner's requesting knowledge from the scholar and asking him to teach him.
8. It is recommended to greet with peace upon meeting someone, and it is obligatory to respond to the greeting. It is also recommended to repeat the greeting if the meeting occurs again, even if it is shortly after the previous one, and a response is required each time.