question #1 Sahih Muslim 539a, Book 5, Hadith 43 : What changes were made to the conduct of prayer after the revelation of a specific verse?

We used to talk while engaged in prayer and a person talked with a companion on his side in prayer till (this verse) was revealed:” And stand before Allah in devout obedience” (ii, 238) and we were commanded to observe silence (in prayer) and were forbidden to speak.