Sunan Abi Dawud 2378
سنن أبي داود#2378Hasanحَدَّثَنَا وَهْبُ بْنُ بَقِيَّةَ، أَخْبَرَنَا أَبُو مُعَاوِيَةَ، عَنْ عُتْبَةَ، عَنْ أَبِي مُعَاذٍ، عَنْ عُبَيْدِ اللَّهِ بْنِ أَبِي بَكْرِ بْنِ أَنَسٍ، عَنْ أَنَسِ بْنِ مَالِكٍ، أَنَّهُ كَانَ يَكْتَحِلُ وَهُوَ صَائِمٌ .
Ubaid Allah b. Abu Bakr b. Anas reported on the authority of Anas b. Malik that he used to apply collyrium when he was fasting
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-AlbaniHasan
Muhammad Muhyi Al-Din Abdul HamidHasan
Zubair Ali ZaiDaif
In-book reference: 14:66