Sahih Muslim 2344 a
Jabir b. Samura was asked about the old age of Allah's Apostle (ﷺ). He said:
When he oiled his head nothing was seen (as a mark of old age) and when he did not apply oil something (of the old age) became visible.
وَحَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا أَبُو دَاوُدَ، سُلَيْمَانُ بْنُ دَاوُدَ حَدَّثَنَا شُعْبَةُ، عَنْ سِمَاكِ،
 بْنِ حَرْبٍ قَالَ سَمِعْتُ جَابِرَ بْنَ سَمُرَةَ، سُئِلَ عَنْ شَيْبِ النَّبِيِّ، صلى الله عليه وسلم فَقَالَ
 كَانَ إِذَا دَهَنَ رَأْسَهُ لَمْ يُرَ مِنْهُ شَىْءٌ وَإِذَا لَمْ يَدْهُنْ رُئِيَ مِنْهُ ‏.‏