1- What is the ruling on the Imam and congregants staying in the mosque on the 27th night of Ramadan until the Fajr prayer, to the exclusion of other nights? 2- Is it permissible for someone who has prayed Witr with the Imam to pray another unit (rak'ah) and then pray Witr a second time after the night vigil (qiyam al-layl)?

There is no harm in observing the night mentioned; if it coincides with Laylat al-Qadr (the Night of Decree), there is immense reward in it. If it does not coincide with it, there is still the reward for observing night prayers and obeying Allah, as well as fulfilling the Prophet's command to seek Laylat al-Qadr. If a person prays Witr with the Imam and then wishes to observe night prayers, there are two opinions regarding this: The first is that he prays as much as he wishes without breaking his Witr and does not pray Witr a second time. The second is that he prays one rak'ah to break his Witr, then prays as much as he wishes, and then prays Witr afterward.