‏الصلاة : Hadeeth No:739 Anas reported: Bilal was commanded (by the Prophet) to repeat the phrases twice in Adhan, and once in lqama....

‏الجهاد والسير‏ : Hadeeth No:4349 It is reported by Zuhri that this tradition was narrated to him by Malik b. Aus who said: Umar b. al-Khattab sent for me and I came to him when the day had advanced. I found him in his house sitting on his bare bed-stead, reclining on a leather pillow. He said (to me): Malik, some people of your tri...