Muwatta Malik 375

Arabic

حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّ عُمَرَ بْنَ الْخَطَّابِ، كَانَ يَأْمُرُ بِتَسْوِيَةِ الصُّفُوفِ فَإِذَا جَاءُوهُ فَأَخْبَرُوهُ أَنْ قَدِ اسْتَوَتْ كَبَّرَ ‏.‏

Translation

Yahya related to me from Malik from Nafi that Umar ibn al-Khattab used to order the rows to be straightened, and when they had come to him and told him that the rows were straight he would say the takbir

Authenticity

Sahih · Salim al-Hilali

Reference