[2:238] Maintain (ḥāfiẓū) the prayers and the middle prayer, and stand submissive to God.
To maintain (muḥāfaẓa) the prayers is to come to them with awe and to leave with reverence, and to ask to be in a state of continual presence with good manners. The middle prayer is mentioned without clearly defining it so that you will observe each of them thinking it is the one and will not neglect any.