Sahih al-Bukhari 884
صحيح البخاري#884Sahihحَدَّثَنَا أَبُو الْيَمَانِ، قَالَ أَخْبَرَنَا شُعَيْبٌ، عَنِ الزُّهْرِيِّ، قَالَ طَاوُسٌ قُلْتُ لاِبْنِ عَبَّاسٍ ذَكَرُوا أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ " اغْتَسِلُوا يَوْمَ الْجُمُعَةِ وَاغْسِلُوا رُءُوسَكُمْ وَإِنْ لَمْ تَكُونُوا جُنُبًا، وَأَصِيبُوا مِنَ الطِّيبِ ". قَالَ ابْنُ عَبَّاسٍ أَمَّا الْغُسْلُ فَنَعَمْ، وَأَمَّا الطِّيبُ فَلاَ أَدْرِي.
Narrated Tawus:I said to Ibn `Abbas, "The people are narrating that the Prophet (ﷺ) said, 'Take a bath on Friday and wash your heads (i.e. take a thorough bath) even though you were not Junub and use perfume'." On that Ibn `Abbas replied, "I know about the bath, (i.e. it is essential) but I do not know about the perfume (i.e. whether it is essential or not)
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:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 11:9