question #1 Sahih Muslim 1101b, Book 13, Hadith 66 : What is the significance of breaking the fast at the correct time during a journey?

We were with the Messenger of Allah (ﷺ) on a journey. When the sun sank he said to a person: Get down and prepare barley meal for us. Upon this he said: Messenger of Allah, let there be dusk. (He the Holy Prophet) said: Get down and prepare barley meal for us. He (the person) said: There is still (the light of) day upon us. (But) he got down (in obedience to the command of the Holy Prophet) and prepared a barley meal for him and he (the Holy Prophet) drank that (liquid meal) and then said: When you see the night approaching from that side (west) (and he pointed towards the east with his hand), then the observer of the fast should break it.