مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2372
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Tawoos al-Yamani said: I said to ‘Abdullah bin ‘Abbas (رضي الله عنه): They are saying that the Messenger of Allah (ﷺ) said: "Do ghusl on Friday, and wash your heads, even if you are not junub, and put on perfume." And Ibn 'Abbas said: As for perfume, I do not know, but as for ghusl, then yes.
Musnad Ahmad 2383A saheeh hadeeth; this is a hasan isnad]