Sahih al-Bukhari, Hadith 884 ⓘ
Narrated Tawus: I said to Ibn `Abbas, "The people are narrating that the Prophet 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.)
حَدَّثَنَا 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.
also referenced under: Book 11, Hadith 9 (In-Book) & Volume 2, Book 13, Hadith 9 (USC-MSA)