Yahya related to me from Malik from al-Ala ibn Abd ar-Rahman ibnYaqub from his father and Ishaq ibn Abdullah that they informed himthat they heard Abu Hurayra say, "The Messenger of Allah, may Allahbless him and grant him peace, said, 'When the iqama is called forprayer, do not come to it running, but come with calmness. Pray whatyou catch and complete what you miss. You are in prayer as long asyour aim is the prayer.' "
App reference: Book 3, Hadith 4
USC-MSA web (English) reference: Book 3, Hadith 4
Arabic reference: Book 3, Hadith 150