Is it permissible to delay the Ishā prayer without an excuse?

The time for the Ishā’ prayer begins from the disappearance of the red twilight until midnight, according to the more preponderant opinion. It is not permissible to delay it until after midnight except for an excuse, based on the Prophet’s (peace be upon him) saying: "The time for Ishā’ is until midnight." Whoever delays it without an excuse commits a sin. It is obligatory for a Muslim to perform the fard (obligatory) prayer in the mosque in congregation, and it is not permissible to abandon the congregation except for an excuse.