Hadith 168

أَخْبَرَنَا أَخْبَرَنَا عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ، حَدَّثَنَا ابْنُ عُيَيْنَةَ، عَنْ عُبَيْدِ اللَّهِ بْنِ أَبِي يَزِيدَ، قَالَ: كَانَ ابْنُ عَبَّاسٍ رَضِيَ اللهُ عَنْهُ "إِذَا سُئِلَ عَنْ الْأَمْرِ فَكَانَ فِي الْقُرْآنِ، أَخْبَرَ بِهِ، وَإِنْ لَمْ يَكُنْ فِي الْقُرْآنِ وَكَانَ عَنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ، أَخْبَرَ بِهِ، فَإِنْ لَمْ يَكُنْ، فَعَنْ أَبِي بَكْرٍ، وَعُمَرَ رَضِيَ اللهُ عَنْهُمَا فَإِنْ لَمْ يَكُنْ، قَالَ فِيهِ بِرَأْيِهِ".
It is narrated from Ubaidullah bin Abi Yazid that when a matter was asked of Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both), if it was mentioned in the Holy Qur'an, he would inform of it. If it was not in the Noble Qur'an but found in the hadith of the Messenger of Allah (peace and blessings be upon him), he would inform of it. And if it was not in the hadith either, he would look at the verdicts of Sayyiduna Abu Bakr and Umar (may Allah be pleased with them both). If he did not find the matter there either, then he would express his own opinion regarding it.
Hadith Reference سنن دارمي / مقدمه / 168
Hadith Grading تحقیق (حسین سلیم أسد الدارانی): إسناده صحيح، [مكتبه الشامله نمبر: 168]
Hadith Takhrij اس اثر کی سند صحیح ہے۔ دیکھئے: [المستدرك 127/1] ، [الفقيه 203/1] ، [آداب القاضي 115/10]