Bulugh al-Maram
The Book of Prayer — Hadith #504
وَعَنْ أَبِي هُرَيْرَةَ - رضى الله عنه - عَنْ اَلنَّبِيِّ - صلى الله عليه وسلم -قَالَ: { إِذَا سَمِعْتُمْ اَلْإِقَامَةَ فَامْشُوا إِلَى اَلصَّلَاةِ, وَعَلَيْكُمْ اَلسَّكِينَةُ وَالْوَقَارُ, وَلَا تُسْرِعُوا, فَمَا أَدْرَكْتُمْ فَصَلُّوا, وَمَا فَاتَكُمْ فَأَتِمُّوا } مُتَّفَقٌ عَلَيْهِ, وَاللَّفْظُ لِلْبُخَارِيِّ . 1 .1 - صحيح. رواه البخاري (636)، ومسلم (602).
The Prophet (ﷺ) said: “If you hear the Iqamah, you must walk to the prayer (place) with tranquility and dignity, and do not hasten; and whatever portion of the prayer you get (along with the Imam) offer it, and complete afterwards whatever you missed.
[Agreed upon, and the wording is al-Bukhari’s).