"My father narrated to me that a paternal uncle of his, who had been at Badr, said: 'I was sitting with the Messenger of Allah ﷺ in the masjid when a man came in and prayed two rak'ahs, then he came and greeted the Prophet ﷺ with salam. The Prophet ﷺ had been watching him as he prayed, so he returned his salam, then he said: "Go back and pray, for you have not prayed." So he went back and prayed, then he came back and greeted the Prophet ﷺ with salam. He returned the salam, then he said: "Go back and pray, for you have not prayed." The third or fourth time this happened, then the man said: "By the One Who revealed the Book to you, I have done my best and have tried hard; show me and teach me." He said: 'When you want to pray, perform wudu and do it well, then turn to face the Qiblah and say the takbir. Then recite the Quran, then bow until you are at ease in bowing. Then stand up until you are standing straight, then prostrate until you are at ease prostrating, then sit up until you are at ease sitting, then prostrate until you are at ease prostrating, then get up. If you complete the prayer in this manner you wil hve done it properly, and whatever you do less than this is lacking from you prayer.'" (Using translation from Nasāʾī 1314)   

كُنَّا مَعَ رَسُولِ اللهِ ﷺ فِي الْمَسْجِدِ فَإِذَا رَجُلٌ يُصَلِّي فِي نَاحِيَةِ الْمَسْجِدِ قَالَ وَرَسُولُ اللهِ ﷺ يَرْمُقُهُ وَلَا يَفْطِنُ لَهُ فَلَمَّا صَلَّى أَقْبَلَ حَتَّى وَقَفَ عَلَى النَّبِيِّ ﷺ فَسَلَّمَ عَلَيْهِ فَرَدَّ عَلَيْهِ النَّبِيُّ ﷺ ثُمَّ قَالَ «ارْجِعْ فَصَلِّ فَإِنَّكَ لَمْ تُصَلِّ» فَرَجَعَ فَصَلَّى ثُمَّ أَقْبَلَ فَسَلَّمَ عَلَى النَّبِيِّ ﷺ فَرَدَّ عَلَيْهِ ثُمَّ قَالَ «ارْجِعْ فَصَلِّ فَإِنَّكَ لَمْ تُصَلِّ» فَصَنَعَ ذَلِكَ مَرَّتَيْنِ أَوْ ثَلَاثًا قَالَ الرَّجُلُ وَالَّذِي أَنْزَلَ عَلَيْكَ الْكِتَابَ بِالْحَقِّ لَقَدْ جَهَدْتُ وَحَرَصْتُ فَأَرِنِي يَا رَسُولَ اللهِ وَعَلِّمْنِي فَقَالَ رَسُولُ اللهِ ﷺ «إِذَا أَرَدْتَ أنْ تُصَلِّيَ فَتَوَضَّأْ وَأَحْسِنْ وُضُوءَكَ كَمَا أَمَرَ اللهُ ثُمَّ اقْرَأْ ثُمَّ ارْكَعْ حَتَّى تَطْمَئِنَّ رَاكِعًا ثُمَّ ارْفَعْ حَتَّى تَعْتَدِلَ قَائِمًا ثُمَّ اسْجُدْ حَتَّى تَطْمَئِنَّ سَاجِدًا ثُمَّ ارْفَعْ حَتَّى تَسْتَوِيَ قَاعِدًا ثُمَّ اسْجُدْ حَتَّى تَطْمَئِنَّ سَاجِدًا ثُمَّ قُمْ فَإِنْ أَتْمَمْتَ صَلَاتَكَ عَلَى هَذَا فَقَدْ تَمَّتْ وَإِنِ انْتَقَصْتَ مِنْ ذَلِكَ فَإِنَّمَا تُنْقِصُهُ مِنْ صَلَاتِكَ»  

"One day Messenger of Allah was sitting in the Masjid" Rifa'ah said: "And we were with him. Then what appeared to be a Bedouin man entered to pray, but he performed his Salat in a very brief manner. He then got up and greeted the prophet with Salam. The Prophet said (returning the greeting): 'And upon you. Go back and perform Salat, for indeed you have no prayed.' So he returned to perform Salat then came and greeted the Prophet with Salam. So he (the Prophet) said (returning the greeting): 'And upon you. Go back and perform Salat, for indeed you have not prayed.' [He did that] two or three times, each time coming to the Prophet, greeted the Prophet with Salam and the Prophet saying: 'And upon you. Go back and perform Salat, for indeed you have not prayed.' - until the people got scared and became very worried that one whose prayer was so brief had not actually prayed. Then in the end the man said: 'Then show me, and teach me, for I am a human who has suffered and is mistaken.' So he said: 'Alright. When you stand for Salat then perform Wudu as Allah ordered you. Then say the Tashahhud, and the Iqamah as well. If you know any Quran then recite it, if not then praise Allah, mention His greatness, and the Tahlil. Then bow such that you are at rest in your bowing, then stand completely, then prostrate completely, then sit such that you are at rest while sitting them stand. When you have done that, then you have completed your Salat, and if you leave out something, then you have made your Salat deficient.' And this was easier on them than the first matter, because if some of this was deficient, It would only reduce the reward of his Salat, it would not have gone entirely. " (Using translation from Tirmidhī 302)   

أَنَّ رَسُولَ اللهِ ﷺ بَيْنَا هُوَ جَالِسٌ فِي الْمَسْجِدِ يَوْمًا قَالَ رِفَاعَةُ وَنَحْنُ عِنْدَهُ إِذَا جَاءَ رَجُلٌ كَالْبَدَوِيِّ فَصَلَّى فَأَخَفَّ صَلَاتَهُ ثُمَّ انْصَرَفَ فَسَلَّمَ عَلَى النَّبِيِّ ﷺ فَقَالَ النَّبِيُّ ﷺ «وَعَلَيْكَ فَارْجِعْ فَصَلِّ فَإِنَّكَ لَمْ تُصَلِّ فَرَجَعَ فَصَلَّى» ثُمَّ جَاءَ فَسَلَّمَ عَلَيْهِ فَقَالَ «وَعَلَيْكَ فَارْجِعْ فَصَلِّ فَإِنَّكَ لَمْ تُصَلِّ» فَفَعَلَ ذَلِكَ مَرَّتَيْنِ أَوْ ثَلَاثًا كُلُّ ذَلِكَ يَأْتِي النَّبِيَّ ﷺ فَيُسَلِّمُ عَلَى النَّبِيِّ ﷺ فَيَقُولُ النَّبِيُّ ﷺ وَعَلَيْكَ فَارْجِعْ فَإِنَّكَ لَمْ تُصَلِّ فَعَاثَ النَّاسُ وَكَبُرَ ذَلِكَ عَلَيْهِمْ أَنْ يَكُونَ مَنْ أَخَفَّ صَلَاتَهُ لَمْ يُصَلِّ فَقَالَ الرَّجُلُ فِي آخِرِ ذَلِكَ فَأَرِنِي أَوْ عَلِّمْنِي فَإِنَّمَا أَنَا بَشَرٌ أُصِيبُ وَأُخْطِئُ فَقَالَ لِلرَّجُلِ «إِذَا قُمْتَ إِلَى الصَّلَاةِ فَتَوَضَّأْ كَمَا أَمَرَكَ اللهُ ثُمَّ تَشَهَّدْ فَأَقِمْ ثُمَّ كَبِّرْ فَإِنْ كَانَ مَعَكَ قُرْآنٌ فَاقْرَأْ بِهِ وَإِلَّا فَاحْمَدِ اللهَ وَكَبِّرْهُ وَهَلِّلْهُ ثُمَّ ارْكَعْ فَاطْمَئِنَّ رَاكِعًا ثُمَّ اعْتَدِلْ قَائِمًا ثُمَّ اسْجُدْ فَاعْتَدِلْ سَاجِدًا ثُمَّ اجْلِسْ فَاطْمَئِنَّ جَالِسًا ثُمَّ قُمْ فَإِذَا فَعَلْتَ ذَلِكَ فَقَدْ تَمَّتْ صَلَاتُكَ وَإِنِ انْتَقَصْتَ مِنْهَا شَيْئًا انْتَقَصَ مِنْ صَلَاتِكَ وَلَمْ تَذْهَبْ كُلُّهَا»