Sunan an-Nasa'i 5073
سنن النسائي#5073SahihIt was narrated that Ibn 'Umar said:"The Messenger of Allah [SAW] said: 'Change gray hair, but do not imitate the Jews
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih
In-book reference: 48:34