Repentance — punishment — forgiveness

Some muslims did not join Prophet PBUH on his journey to Tabook. They were true muslims however one neglect fell heavy upon them. They were restricted contact from all muslims for 50 days. They were told to stay at distance from their wives. During these days, they tried to ask for forgiveness but the punishment was there and they had to undergo it. They repented and stayed within the boundaries of great muslims. After 50 days, the verses were revealed to Prophet PBUH from Allah swt, saying the repentance of these muslims has been accepted. It was a good day for muslims — inside they all wanted their commrades with them. And Allah swt brought the news of delight soon to them.

It depicts it is important to stay steadfast in religion when a sin happens, and while the punishment is given. Allah accepts efforts of believers — even after they have sinned.