As for the prostration mentioned in Sād, the scholars disagree: is it a prostration of gratitude or a prostration of recitation? Allah knows best.

When one prostrates for recitation he should pronounce the takbīr (saying “Allāhu Akbar”), for Ibn ʿUmar relates: “The Prophet would recite the Qur’an to us, and whenever he came to a verse of prostration he would say the takbīr, then prostrate, and we would prostrate with him.” Reported by Abū Dāwūd.

In this prostration he says, “Subḥāna Rabbī al-Aʿlā (Glory be to my Lord, the Most High),” just as he does during the prayer prostration; and if he instead says, “My face has prostrated to Allah Who created and fashioned it, and brought forth its hearing and sight by His power and might. O Allah, record for me a reward, remove from me a burden, store it up for me with You, and accept it from me just as You accepted it from Your servant David,” there is no harm.

Performing the prostration of recitation from a standing position is better than performing it while seated.

O Muslim, the avenues of goodness are many, so exert yourself in them with seriousness and diligence, and be sincere in word and deed—perhaps Allah will count you among the blessed.