Yahya related to me from Malik from Nafi that Abdullah ibn Umar would guard against animals and camels which were young or had physical defects as sacrifices.
Malik said, "That is what I like best of what I have heard ."

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، كَانَ يَتَّقِي مِنَ الضَّحَايَا وَالْبُدْنِ الَّتِي لَمْ تُسِنَّ وَالَّتِي نَقَصَ مِنْ خَلْقِهَا . قَالَ مَالِكٌ وَهَذَا أَحَبُّ مَا سَمِعْتُ إِلَىَّ .