Sahih Bukhari Volume 8, Book 86, Hadith 6788

حَدَّثَنَا يَحْيَى بْنُ بُكَيْرٍ، حَدَّثَنَا اللَّيْثُ، عَنْ عُقَيْلٍ، عَنِ ابْنِ شِهَابٍ، عَنْ عُرْوَةَ، عَنْ عَائِشَةَ ـ رضى الله عنها ـ قَالَتْ مَا خُيِّرَ النَّبِيُّ صلى الله عليه وسلم بَيْنَ أَمْرَيْنِ إِلاَّ اخْتَارَ أَيْسَرَهُمَا، مَا لَمْ يَأْثَمْ، فَإِذَا كَانَ الإِثْمُ كَانَ أَبْعَدَهُمَا مِنْهُ، وَاللَّهِ مَا انْتَقَمَ لِنَفْسِهِ فِي شَىْءٍ يُؤْتَى إِلَيْهِ قَطُّ، حَتَّى تُنْتَهَكَ حُرُمَاتُ اللَّهِ، فَيَنْتَقِمُ لِلَّهِ‏.‏

Narrated By 'Aisha : Whenever the Prophet was given an option between two things, he used to select the easier of the tow as long as it was not sinful; but if it was sinful, he would remain far from it. By Allah, he never took revenge for himself concerning any matter that was presented to him, but when Allah's Limits were transgressed, he would take revenge for Allah's Sake.