Sunan an-Nasa'i, Hadith 5080 ⓘ
It was narrated that Abu Dharr said: "The Messenger of Allah [SAW] said: 'The best things with which you can change gray hair are Henna and Katam.'"
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا عَبْثَرٌ، عَنِ الأَجْلَحِ، عَنْ عَبْدِ اللَّهِ بْنِ بُرَيْدَةَ، عَنْ أَبِي الأَسْوَدِ الدِّيلِيِّ، عَنْ أَبِي ذَرٍّ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِنَّ أَحْسَنَ مَا غَيَّرْتُمْ بِهِ الشَّيْبَ الْحِنَّاءُ وَالْكَتَمُ " . خَالَفَهُ الْجُرَيْرِيُّ وَكَهْمَسٌ .
also referenced under: Book 48, Hadith 41 (In-Book) & Volume 6, Book 48, Hadith 5083 (DarusSalam)