Sahih Bukhari Volume 009, Book 089, Hadith Number 297.
Narrated By Ibn 'Umar : Allah's Apostle sent an army unit headed by Usama bin Zaid and the people criticized his leadership. The Prophet said (to the people), "If you are criticizing his leadership now, then you used to criticize his father's leadership before. By Allah, he (Usama's father) deserved the leadership and used to be one of the most beloved persons to me, and now his son (Usama) is one of the most beloved persons to me after him. " (See Hadith No. 745, Vol. 5)