Sahih Bukhari Volume 5, Book 64, Hadith 4252

حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، حَدَّثَنَا سُفْيَانُ بْنُ سَعِيدٍ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ دِينَارٍ، عَنِ ابْنِ عُمَرَ ـ رضى الله عنهما ـ قَالَ أَمَّرَ رَسُولُ اللَّهِ صلى الله عليه وسلم أُسَامَةَ عَلَى قَوْمٍ، فَطَعَنُوا فِي إِمَارَتِهِ، فَقَالَ ‏"‏ إِنْ تَطْعَنُوا فِي إِمَارَتِهِ، فَقَدْ طَعَنْتُمْ فِي إِمَارَةِ أَبِيهِ مِنْ قَبْلِهِ، وَايْمُ اللَّهِ لَقَدْ كَانَ خَلِيقًا لِلإِمَارَةِ، وَإِنْ كَانَ مِنْ أَحَبِّ النَّاسِ إِلَىَّ، وَإِنَّ هَذَا لَمِنْ أَحَبِّ النَّاسِ إِلَىَّ بَعْدَهُ ‏"‏‏

Narrated By Ibn Umar : Allah's Apostle appointed Usama bin Zaid as the commander of some people. Those people criticized his leadership. The Prophet said, "If you speak ill of his leadership, you have already spoken ill of his father's leadership before. By Allah, he deserved to be a Commander, and he was one of the most beloved persons to me and now this (i.e. Usama) is one of the most beloved persons to me after him.