Sunan an-Nasa'i 5114

أَخْبَرَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، قَالَ حَدَّثَنَا أَبُو دَاوُدَ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ سِمَاكٍ، قَالَ سَمِعْتُ جَابِرَ بْنَ سَمُرَةَ، سُئِلَ عَنْ شَيْبِ، رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ كَانَ إِذَا ادُّهِنَ رَأْسُهُ لَمْ يُرَ مِنْهُ وَإِذَا لَمْ يُدَّهَنْ رُئِيَ مِنْهُ ‏.‏

It was narrated that Simak said:"I heard Jabir bin Samurah being asked about the gray hairs of the Prophet [SAW]. He said: 'If he put oil on his head they could not be seen, but if he did not put oil on his head, they could be seen

Reference

Sunan an-Nasa'i 5114

In-book

Book 48, Hadith 75