I am aware that the best time to pray Tahajjud is the last third of the night.
1. My Question is If I am to pray Tahajjud in the first third of the night after Isha. Is it obligatory that i sleep in the period between Isha and Tahajjud prayers?
2. If yes, for how long should i sleep? (Will a few minutes sleep be sufficient or just dozing off is enough)
Opinions of both Shafi'i and Hanafi Madhab will be appreciated.