It is narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him) that the Prophet Muhammad (peace and blessings be upon him) said: "Join your rows well and keep the rows close together and align your necks. By the One in Whose hand is the soul of Muhammad, indeed I see that Satan enters through the gaps in the rows as if he were a small goat." Janab Muslim bin Ibrahim says that "al-khadhaf" means a small goat.