Make sure you are certain before taking any action especially when it comes to religious matters. Take into consideration what other people in your community may do before making decisions for yourself.

This hadith is about fasting as an atonement for breaking a vow or oath. It teaches us that we should not fast as an atonement unless we are certain that the people of a certain city of Muslims had fasted on Sunday. We must be sure and have certainty before taking any action, especially when it comes to religious matters. We must also be aware that our actions can affect others, and so we must take into consideration what other people in our community may do before making decisions for ourselves.