What is the ruling on saying "Lord, protect me from Your torment on the Day You resurrect Your servants" three times after the obligatory prayer, and is it considered one of the post-prayer remembrances?

Among the reported remembrances (dhikr) after the obligatory prayer is the saying: "My Lord, protect me from Your punishment the Day You resurrect—or gather—Your servants." This has been authentically reported from the Prophet, peace and blessings be upon him, who used to say it silently, and sometimes his companion would hear him. However, repeating this remembrance three times after the obligatory prayer is not authentically established. Nevertheless, there is no harm in saying it three times without believing in its Sunnah on this specific manner or making it a regular practice. This remembrance is also among the reported remembrances recited before sleep.