Is prayer accepted if one is not humble during it, and is it true that a person will be struck by his prayer on the Day of Resurrection if he was not humble during it?

Humility (Khushu') is the soul of prayer, but it is not a condition for its validity according to the majority of scholars. That is, the prayer is not invalidated by its absence, but its reward decreases and may even vanish. It is mentioned in the Sunan that the first thing a servant will be held accountable for on the Day of Judgment is prayer. If it is deficient, it will be completed from his voluntary acts of worship. In Al-Tabarani's Mu'jam, it is stated that a complete prayer, performed on time, with perfect ablution, humility, bowing, and prostration, emerges bright and luminous, whereas an incomplete prayer emerges dark and gloomy, and is struck upon the faces of its performers.