Sahih Bukhari
Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Volume: 005 / Book Number: 059 / Hadith Number: 745
Narrated 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."