Sahih Muslim , Hadith 1867 ⓘ
It has been narrated on the authority of Abdullah b. 'Umar who said: We used to take oath to the Messenger of Allah that we would listen to and obey his orders. He would tell us (to say in the oath): As far as it lies in my power.
حَدَّثَنَا يَحْيَى بْنُ أَيُّوبَ، وَقُتَيْبَةُ، وَابْنُ، حُجْرٍ - وَاللَّفْظُ لاِبْنِ أَيُّوبَ - قَالُوا حَدَّثَنَا إِسْمَاعِيلُ، - وَهُوَ ابْنُ جَعْفَرٍ - أَخْبَرَنِي عَبْدُ اللَّهِ بْنُ دِينَارٍ، أَنَّهُ سَمِعَ عَبْدَ اللَّهِ بْنَ عُمَرَ، يَقُولُ كُنَّا نُبَايِعُ رَسُولَ اللَّهِ صلى الله عليه وسلم عَلَى السَّمْعِ وَالطَّاعَةِ يَقُولُ لَنَا " فِيمَا اسْتَطَعْتَ " .
also referenced under: Book 33, Hadith 132 (In-Book) & Book 20, Hadith 4604 (USC-MSA)