Jami` at-Tirmidhi 475
جامع الترمذي#475SahihJubair narrated from Abu Ad-Darda, or Abu Dharr, that :Allah's Messenger narrated that Allah, Blessed and Most High said: "Son of Adam: Perform four Rak'ah for Me in the beginning of the day it will suffice you for the latter part of it
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih
In-book reference: 3:23