Sunan Abi Dawud 5034
سنن أبي داود#5034Hasanحَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَحْيَى، عَنِ ابْنِ عَجْلاَنَ، قَالَ حَدَّثَنِي سَعِيدُ بْنُ أَبِي سَعِيدٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ شَمِّتْ أَخَاكَ ثَلاَثًا فَمَا زَادَ فَهُوَ زُكَامٌ .
Narrated AbuHurayrah: Respond three times to your brother when he sneezes, and if he sneezes more often, he has a cold in his head
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 ZaiIsnaad Hasan
In-book reference: 43:262