Musnad Ahmad 1034:101

Muhammad ibn Ubayd narrated to us, al-A’mash narrated to us, from Shaqiq, who said: Hudhayfah said: "The person most similar to Muhammad, may Allah bless him and grant him peace, in guidance, conduct, and demeanor is Abdullah ibn Mas’ud, from the time he goes out until he returns. I do not know what he does in his house."