Summarized Fatawaa
• Is it permissible to offer Tahajjud prayer after Witr prayer ?
It is permissible to offer voluntary prayer after Witr(an odd number prayer performed between Isha`a and Fajr) prayer. However, it is desirable that the night prayer be ended with Witr. Therefore, it is desirable for one, who thought that he was most probably going to wake up at night in order to offer Tahajjud, to offer Witr after it, but one, who fears that he might not wake up, should offer Witr before going to bed.
• How is night prayer offered ?
Night prayer is offering voluntary prayer after Maghrib and before Fajr(dawn). As for Tahajjud, it is offering voluntary prayer at night after waking up voluntarily, and for Allah`s sake as He says: “And pray in the small watches of the morning: (it would be) an additional prayer (or spiritual profit) for thee: soon will thy Lord raise thee to a Station of Praise and Glory!”{Al-Isra`/ 79}. Offering Tahajjud is better than offering voluntary prayer before going to bed.
• What is the ruling on reciting the Chapter after Al-Faatihah , and what should a worshiper who forgets it do?
Any other part of Qur'an that a worshiper reads after Al-Faatihah during the first and the second Rak`ahs is a Sunnah, and forgetting to do so doesn`t nullify prayer, and doesn`t require performing Sujood As-Sahw ( prostration of forgetfulness).
• Is it permissible for a wife to leave her house without asking her husband?
It is impermissible for the wife to leave her house without asking her husband except for a sound reason.