Hadith 110
قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ : " إِذَا نُودِيَ بِالصَّلاةِ، فَأْتُوهَا وَأَنْتُمْ تَمْشُونَ وَعَلَيْكُمُ السَّكِينَةُ، فَمَا أَدْرَكْتُمْ فَصَلُّوا، وَمَا سُبِقْتُمْ فَأَتِمُّوا "
And the Messenger of Allah, peace and blessings be upon him, said: "When the call to prayer is given, come to the prayer with calmness and tranquility. Then whatever part of the prayer you catch, perform it, and whatever you miss, complete it (afterwards)."