'Fast' in the Bible

"Whenever you fast, don't be gloomy like the hypocrites, because they put on sad faces to show others they are fasting. I tell all of you with certainty, they have their full reward!

But when you fast, put oil on your head and wash your face,

Then John's disciples came to Jesus and asked, "Why do we and the Pharisees fast often, but your disciples don't fast?"

Jesus asked them, "The wedding guests can't mourn as long as the groom is with them, can they? But the time will come when the groom will be taken away from them, and then they will fast."