Musnad Ahmad 32:2025

Abdullah narrated to us, Muhammad ibn Ahmad al-Junaydi narrated to me, a man narrated to us, Shu'bah narrated to us, from Qatadah—and he was impressed by this hadith—from Anas, who said: The Messenger of Allah, peace and blessings of Allah be upon him, said: "Straighten your rows, for the straightening of the row is part of the perfection of the prayer."