While we said our prayer with the Messenger of Allah ﷺ he heard tumult. (At the end of the prayer) he (the Holy Prophet) said: What is the matter with you? They said: We hastened to prayer. He (the Holy Prophet) said: Don't do that; when you come for prayer, there should be tranquillity upon you. Pray (along with the Imam) what you can find and complete what preceded you.

أَخْبَرَهُ قَالَ بَيْنَمَا نَحْنُ نُصَلِّي مَعَ رَسُولِ اللَّهِ ﷺ فَسَمِعَ جَلَبَةً فَقَالَ مَا شَأْنُكُمْ قَالُوا اسْتَعْجَلْنَا إِلَى الصَّلاَةِ قَالَ فَلاَ تَفْعَلُوا إِذَا أَتَيْتُمُ الصَّلاَةَ فَعَلَيْكُمُ السَّكِينَةُ فَمَا أَدْرَكْتُمْ فَصَلُّوا وَمَا سَبَقَكُمْ فَأَتِمُّوا