Is it permissible to say "Rabbana laka al-hamd wa al-shukr" (Our Lord, to You be all praise and gratitude) after rising from bowing in prayer, knowing that the word "al-shukr" (gratitude) was not reported from the Prophet, peace and blessings be upon him, and is this considered an error that warrants strong condemnation of the one who does it?

The word "al-shukr" (gratitude/thanks) is not part of the prescribed dhikr (remembrance) upon rising from ruku’ (bowing); therefore, it should not be uttered at that moment. However, outside of rising from ruku’, there is no harm in saying it, because all praise (hamd) and gratitude (shukr) belong to Allah the Almighty. One who explains a matter related to religion should do so in a calm and composed manner, free from emotion and tension, for a gentle and convincing approach is more impactful and beneficial. This was the method of the Prophet, peace and blessings be upon him, in enjoining good, forbidding evil, inviting people to Islam, and guiding them. The aforementioned Imam should be excused, and one should have a good opinion of him, for he intends nothing but good. Some people may be sharp in their speech yet have pure intentions and are keen to advise others.