Sayyiduna Abu Hurayrah (may Allah be pleased with him) says: I heard the Messenger of Allah (peace and blessings be upon him) say: "When the iqamah for the prayer is called, do not come to it running; rather, come walking, and hold to tranquillity. Pray what you catch, and complete what you have missed."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5870