Sunan Abi Dawud 141
سنن أبي داود#141Sahihحَدَّثَنَا إِبْرَاهِيمُ بْنُ مُوسَى، حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا ابْنُ أَبِي ذِئْبٍ، عَنْ قَارِظٍ، عَنْ أَبِي غَطَفَانَ، عَنِ ابْنِ عَبَّاسٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " اسْتَنْثِرُوا مَرَّتَيْنِ بَالِغَتَيْنِ أَوْ ثَلاَثًا " .
Narrated Abdullah ibn Abbas: The Messenger of Allah (ﷺ) said: Cleanse your nose well (after snuffing up water) twice or thrice
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Zubair Ali ZaiIsnaad Hasan
In-book reference: 1:141