What is the ruling on delaying joining the Imam in congregational prayer, whether the Imam is fast or not, and what is the ruling on prolonging the prayer (whether Sunnah or obligatory) if that delays others?

The Question: What is the ruling on a congregant lagging a full pillar behind the Imam?

The Answer: If a congregant lags a full pillar behind the Imam—such as the Imam bowing and rising before the congregant begins bowing—and this delay is due to an excuse like drowsiness or the Imam's swiftness, then the congregant should perform what the Imam preceded him in and then catch up, and there is no blame on him. However, if the delay is intentional, the congregant's prayer is nullified due to his deliberate failure to follow his Imam. The Imam should also avoid prolonging the prayer.