[Machine] We used to come to prayer, and when a man comes who has already performed some of the prayer, the one behind him signals to him, saying, "you have preceded me in this and that." So, he completes it. We used to be in the positions of bowing, prostrating, standing, and sitting. Then, one day, I came and I had already performed some of the prayer, and someone signaled to me indicating what I had already performed. So, I said, "I cannot find it in any position except that I was on it." So, I was in the state of those I found them on it. When the Messenger of Allah ﷺ had finished, I stood up and prayed, and the Messenger of Allah ﷺ faced the people and said, "Who was saying this and that?" They said, "Mu'adh bin Jabal." So, the Messenger of Allah ﷺ said, "Whoever precedes in some of the prayer, let him pray with the Imam his prayer. And when the Imam has finished, let him complete what he preceded him with."  

كُنَّا نَأْتِي الصَّلَاةَ فَإِذَا جَاءَ رَجُلٌ وَقَدْ سُبِقَ بِشَيْءٍ مِنَ الصَّلَاةِ فَأَشَارَ إِلَيْهِ الَّذِي يَلِيهِ وَقَدْ سُبِقْتَ بِكَذَا وَكَذَا فَيَقْضِي قَالَ فَكُنَّا بَيْنَ رَاكِعٍ وَسَاجِدٍ وَقَائِمٍ وَقَاعِدٍ فَجِئْتُ يَوْمًا وَقَدْ سُبِقْتُ بِبَعْضِ الصَّلَاةِ وَأُشِيرَ إِلَيَّ بِالَّذِي سُبِقْتُ بِهِ فَقُلْتُ لَا أَجِدُهُ عَلَى حَالٍ إِلَّا كُنْتُ عَلَيْهَا فَكُنْتُ بِحَالِهُمُ الَّذِي وَجَدْتُهُمْ عَلَيْهَا فَلَمَّا فَرَغَ رَسُولُ اللهِ ﷺ قُمْتُ فَصَلَّيْتُ وَاسْتَقْبَلَ رَسُولُ اللهِ ﷺ النَّاسَ فَقَالَ «مَنِ الْقَائِلُ كَذَا وَكَذَا؟» قَالُوا مُعَاذُ بْنُ جَبَلٍ فَقَالَ «قَدْ سَنَّ لَكُمْ مُعَاذٌ فَاقْتَدُوا بِهِ إِذَا جَاءَ أَحَدُكُمْ وَقَدْ سُبِقَ بِشَيْءٍ مِنَ الصَّلَاةِ فَلْيُصَلِّ مَعَ الْإِمَامِ صَلَاتَهُ فَإِذَا فَرَغَ الْإِمَامُ فَلْيَقْضِ مَا سَبَقَهُ بِهِ»