The Prophet ﷺ said to him when he sent him to Yemen, "Beware of indulging in luxury, for the servants of Allah are not those who live in luxury."
أن النبي ﷺ قال له حين بعثه إلى اليمن: إياك والتنعم؛ فإن عباد الله ليسوا بالمتنعمين.
Ahmad (22105), Tabarani in Musnad Shamiyin (1395), and Abu Naeem in Hilya (5/155) — the wording given here is his — all narrated it, all through Baqiya bin Walid, who said, Sari bin Yanam narrated to us, from Mureeh bin Masruq, from Muaz bin Jabal, who said, then he mentioned it.In Musnad Ahmad it has, "Keep luxury away from me," instead of "Beware of luxury."The hadith's isnad is hasan because of Baqiya bin Walid, whose narrations are hasan when he states his source explicitly, and this explicit statement does occur in the narration of Abu Naeem. Sari bin Yanam and Mureeh bin Masruq were narrated from by a number of narrators, and Ibn Hibban mentioned them in Thiqat. His statement, "for the servants of Allah are not people of luxury," means they do not go to excess in what is permissible.