My father (ra) narrated to us. He said: Sa`d b. `Abdullah narrated to us from Ibrahim b. Hashim from al-Husayn b. Yazid al-Nawfali from Isma`il b. Abi Ziyad al-Sukuni from Ja`far b. Muhammad from his father (as). The Prophet (s) prayed over Sa`d b. Mu`adh and said
Ninety thousand angels including Gabriel (as) prayed over him, so I said: “O Gabriel, what made him deserve your praying over him?” So, he said: “He would read qul huwallahu ahad whenever he stood, sat, rode, walked, went, and came back.”