Is the prostration in Surat Sad a prostration of gratitude or a prostration of recitation?

Question:
He says: Honorable Shaykh, may Allah grant you success, is the prostration in Surat Sad a prostration of gratitude or a prostration of recitation? And is it true that it invalidates the prayer if one prostrates?

Answer:
The prostration of gratitude is when a matter reaches him, when a matter reaches him of a newly renewed blessing, a general or specific blessing for him, he prostrates in gratitude, and this is an independent prostration. As for the prostration in Sad, there is disagreement among the scholars: some hold that it is a prostration of gratitude and is not permissible in prayer, while others hold that it is a prostration of recitation. Allah the Exalted said: “So follow their guidance.” Allah, Glorified and Exalted is He, said to our Prophet: “Those are the ones whom Allah has guided,” meaning the previous prophets, “so follow their guidance.” And Dawud prostrated in it, so we prostrate in it following his example by the command of Allah, Blessed and Exalted is He. And this is the stronger position, if Allah wills. Yes.