The ruling on delaying the 'Isha' prayer until six in the evening by sunset time

Q: A female questioner says: What is the ruling on delaying the 'Isha' prayer until six in the evening by sunset time?

A: It is obligatory that the 'Isha' prayer be performed before the middle of the night, and it is not permissible to delay it until the middle of the night; because the Prophet (peace and blessings be upon him) said: So you must pray it before the middle of the night according to the rotation of the celestial bodies. The night increases and decreases, and the criterion is the middle of the night by the hours. If the night is ten hours, it is not permissible for you to delay it until the end of the fifth hour. If the night is eleven hours, it is not permissible to delay it until the end of the fifth and a half hour, and so on. The best time is the first third of the night. Whoever prays it at the beginning of the time, there is nothing wrong with that. However, if one delays it for some time, that is better; because the Messenger (peace and blessings be upon him) used to recommend delaying the 'Isha' prayer for some time. Whoever prays it at the beginning of the time after the disappearance of the twilight (which is the redness in the vertical horizon), there is nothing wrong with that. And success is from Allah.