question #1 Sahih al-Bukhari 116, Book 3, Hadith 58 : What significance does the Prophet place on the night mentioned in the narration?

Once the Prophet (ﷺ) led us in the `Isha’ prayer during the last days of his life and after finishing it (the
prayer) (with Taslim) he said: “Do you realize (the importance of) this night?” Nobody present on the
surface of the earth tonight will be living after the completion of one hundred years from this night.”