Narrated Mujahid:
That he asked Ibn `Abbas, "Is there a prostration Surat-al-Sa`d?" (38.24) Ibn `Abbas said, "Yes," and then recited: "We gave...So follow their guidance." (6.85,90) Then he said, "He (David ) is one them (i.e. those prophets)." Mujahid narrated: I asked Ibn `Abbas (regarding the above Verse). He said, "Your Prophet (Muhammad) was one of those who were ordered to follow them."
USC-MSA web (English) reference: Vol. 6, Book 60, Hadith 156
Arabic reference: Book 65, Hadith 4632