From Sahih Bukhari (Hadith 3417):
Narrated Abu Huraira:The Prophet (ﷺ) said, "The reciting of the Zabur (i.e. Psalms) was made easy for David. He used to order that his riding animals be saddled, and would finish reciting the Zabur before they were saddled. And he would never eat except from the earnings of his manual work
Reference: Bukhari 3417