Sahih Bukhari Volume 005, Book 059, Hadith Number 745.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 59. Military Expeditions Led by the Prophet (PBUH) (Al-Maghaazi)
Narrated By Abdullah bin 'Umar : Allah's Apostle sent troops appointed Usama bin Zaid as their commander. The people criticized his leadership. Allah's Apostle got up and said, "If you (people) are criticizing his (i.e. Usama's) leadership you used to criticize the leadership of his father before. By Allah, he (i.e. Zaid) deserved the leadership indeed, and he used to be one of the most beloved persons to me, and now this (i.e. his son, Usama) is one of the most beloved persons to me after him."