How to perform the night (isha) prayer (Fard)
The night (isha) prayer consists of thirteen rak'ahs: four rak'ahs of sunnah, four rak'ahs of fard, two rak'ahs of the last sunnah and three rak'ahs of witr.
The sunnah of the night (isha) prayer is performed first just like the sunnah of the afternoon prayer except for the intention. That is, salawat are uttered after at-Tahiyyat in the first sitting.
The performance of the fard prayer is just like the fard of the noon and afternoon prayers except for the intention.
The last sunnah is performed just like the sunnah of the evening prayer.
Only the intention is different.