What is the ruling on the prostration (sajdah) that occurs after completing the obligatory prayer?

Prostration is prescribed when there is a reason necessitating it, such as prostration in prayer, prostration of recitation, prostration of thankfulness upon the renewal of a blessing or the warding off of a calamity, and prostration of forgetfulness. As for prostration without a necessitating reason, it is not prescribed. Drawing closer to Allah is not achieved through a singular prostration, just as prostrating after finishing the prayer is not from the guidance of the Prophet (peace be upon him), because it is not legislated in this instance. The scholar Abu Shamah clarified that Islamic law did not intend for drawing closer to Allah through prostration except in prayer or for a specific reason, and that acts of drawing closer have reasons, conditions, times, and pillars without which they are not valid. Thus, acts of worship are built upon divine revelation and adherence.