question #1 Sahih Muslim 451b, Book 4, Hadith 175 : What is the significance of reciting different surahs during the first two rak’ahs of the noon and afternoon prayers?

The Messenger of Allah (ﷺ) would recite in the first two rak’ahs of the noon and afternoon prayers the opening chapter of the Book and another surah. He would sometimes recite loud enough to make audible to us the verse and would recite in the last two rak’ahs Surat al-Faitiha (only).