Hadith 3667
وَعَنِ ابْنِ عُمَرَ رَضِيَ اللَّهُ عَنْهُمَا قَالَ: كُنَّا إِذَا بَايَعْنَا رَسُولِ اللّ��هِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ عَلَى السَّمْعِ وَالطَّاعَةِ يَقُولُ لَنَا: «فِيمَا اسْتَطَعْتُمْ»
Ibn ‘Umar told that when they swore allegiance to God’s Messenger to hear and obey he was saying to them, “In what you are able.” (Bukhari and Muslim.)