I wanted to know what is the punishment for leaving the obligatory prayer. Also explain how to atone for sinning after repentance.
The prayer is so central and foundational an obligation that a believer cannot be imagined to have missed it. The Sharia'h has not devised any punishment. However, if a believer who has missed prayers repents and shows commitment and diligently offers the salah later on can hope to be rewarded and forgiven. Allah Almighty has most mercifully declared that He accepts our true repentance. Breaking the commitment with God (tobah) is a great sin. However, it is not of a legal nature. Therefore, the atonement for the act is again true repentance.