question #1 Sahih Muslim 462a, Book 4, Hadith 195 : What significance does the recitation of specific Surahs hold in Islamic prayers?

Umm al-Fadl daughter of al-Harith heard him reciting:” By those sent forth to spread goodness” (lxxvii.). (Upon this) she remarked: O my son, you reminded me by the recitation of this surah (the fact) that it was the last surah that I heard from the Messenger of Allah (ﷺ) and he recited it in the evening prayer.