Straightening of the Rows in the Mosque

Hazrat Ibn Umar (ra) states that it was the practice of Hazrat Umar (ra) to not say ‘Allahu Akbar’ [i.e. begin the prayer] until the rows were straight. In fact, he had appointed a person for the task of ensuring that the rows were straight. Abu Uthman Nahdi said that as the Iqamah [announcement of the start of prayer] was announced, he would see Hazrat Umar (ra) standing with his back turned towards the ‘qiblah’ [direction of prayer] and would say, “O so and so, move forward” or, “O so and so, move back.” In other words, he would organise the rows. When the rows would be straight, he would turn towards the ‘qiblah’ and say ‘Allahu Akbar’ [i.e. begin the prayer].

(Ibn al-Juzi, Sirat Umar al-Khattab [Al-Azhar, Egypt: al-Matba‘ah al-Misriyyah], p. 165)