Musannaf Ibn Abi Shayba 28:1140

Waki’ narrated to us, he said: Al-Mundhir ibn Tha’labah narrated to us, from ‘Abdullah ibn Buraydah, he said: ‘Umar said to Abu Bakr: "Why did ‘Amr not let the people kindle a fire? Do you not see this one who has withheld from the people their benefits?" He said: So Abu Bakr said: "Leave him standing; the Messenger of Allah, may Allah bless him and grant him peace, appointed him over us because of his knowledge of war."