The Prophet (blessings and peace of Allah be upon him) was very concerned about the matter of prayer, which included his being concerned to teach his companions the beginning and end of the time for each of the five daily prayers. In this hadith, Abu Rafi‘ (may Allah be pleased with him) narrated that they would pray Maghrib with the Prophet (blessings and peace of Allah be upon him), and they would finish the prayer and leave the mosque, and one of them would still be able to see as far as his arrows would fall when shot from a bow. What is meant is that there was still enough light after sunset for them to be able to see where their arrows would land, even though that was so far away. This is a metaphor to indicate that the Prophet (blessings and peace of Allah be upon him) used to pray Maghrib at the beginning of its time, as soon as the sun set. The time for Maghrib begins when the sun disappears. This hadith indicates that we should hasten to pray Maghrib and keep it brief..