Salim bin Abdullah binUmar bin Al-Khattab (May Allah be pleased with them) reported, on the authority of his father, that the Messenger of Allah (sallallaahu ’alayhi wa sallam) said, "What an excellent man Abdullah is! If only he could perform optional prayers at night.'' Salim said that after this, (his father)Abdullah slept very little at night. [Al-Bukhari and Muslim]. Abdullah bin Salam (May Allah be pleased with him) reported: The Prophet (sallallaahu ’alayhi wa sallam) said, "O people, promote the greetings, feed (the poor and needy) and perform Salat when others are asleep so that you will enter Jannah safely.''
Aishah (May Allah be pleased with her) reported: The Prophet (sallallaahu ’alayhi wa sallam) would sleep during the early part of night and stand in Salat during the latter part. [Al-Bukhari and Muslim]. ht (The best time to perform night prayer is the hour before Dawn (the last third of night). If you have determination and make sure that you will get up in the last third of night, then you can pray Isha’ and only double or even and all you want to pray from voluntary prayer after Isha' prayer and delay the Wetr prayer (uneven or sole prayer) to the last third of night. But if you fear or know you will not get up, you should pray the Wetr prayer after Isha’ and if you get up you pray one separate rakat first because one separate rakat with the other one after Isha’ becomes two or double and then you can pray as you want and finally you pray Wetr prayer.)