Majma al-Zawaid 2748 — Prostration

Sayyiduna Sa'd bin Abi Waqqas said: The servant has been commanded to prostrate on seven of his limbs: on his face, his two palms, his two knees and his two feet. Whichever of these he does not place (on the ground), there will be a deficiency to that extent.
Imam Abu Ya'la recorded this narration. Its chain contains a narrator, Musa bin Muhammad bin Hayyan, whom Abu Zur'ah declared da'if (weak). Al-Dhahabi recorded his name with the letter "jim".