Musannaf Ibn Abi Shayba 34:289

Ishaq ibn Sulayman narrated to us, from Abu Sinan, who said: A sheikh narrated to me, from Amr ibn Murrah, who said: The first to establish the *shurtah* (elite guard/police force) was Amr ibn al-Aas. When he fell ill with the illness from which he died, he sent for his *shurtah* and said: "Take your weapons and your mounts and come to me." When they came to him, he said: "I was only preparing you for a day like this. Are you able to turn away from me anything of what I am in?" They said: "Subhan Allah! You say this, when the Messenger of Allah (peace and blessings of Allah be upon him) used to consult you and appoint you as a commander over armies?" He said: "And what do you know? Perhaps the Messenger of Allah (peace and blessings of Allah be upon him) was only reconciling my heart (winning me over) with that."