Does the Hadith: "The first thing for which a person will be held accountable on the Day of Resurrection is prayer; if it is sound, then all his other deeds will be sound, and if it is not sound, then all his other deeds will not be sound" include the abandonment of devotion (khushu') in prayer, or is it specific to its obligatory elements only?

Scholars differ on the ruling concerning khushu' (devotion/humility) in prayer, whether it is recommended, obligatory, or a condition. However, the prayer of one who omits it is valid according to the majority.

Khushu' is included in the reckoning according to all opinions. The deficiency that occurs in the obligatory prayer due to its omission is compensated for by supererogatory (nafl) prayers. And what is deficient in the obligatory prayers, Sunnahs, and prescribed postures regarding khushu', remembrance (dhikr), and supplications (du'a) is completed by voluntary acts.