question #1 Sahih Muslim 396b, Book 4, Hadith 45 : What is the significance of reciting Surat al-Fatiha in every rak’ah of prayer?

If I add nothing to the (recitation) of the Umm al Qur’an (Surat al-Fatiha), would it make the prayer incomplete? He (AbuHuraira) said: If you add to that (if you recite some of verses of the Qur’an along with Surat at-Fatiha) that is better for you. But if you are contented with it (Surat al-Fatiha) only, it is sufficient for you.