Allah Subhanahu wa Ta'ala says (Translation): So woe to those who pray, but are unmindful of their prayers; who make a show (of piety). (Al-Ma'un 107: 4-6)
Note: "…are unmindful of their prayers": includes offering it Qada (after its prescribed time), or offering it inattentively, or offering it irregularly. (Kashfur Rahman)
Note: "…are unmindful of their prayers": includes offering it Qada (after its prescribed time), or offering it inattentively, or offering it irregularly. (Kashfur Rahman)