Jesus compared the situation to a wedding, which calls for joy. He meant that He was the bridegroom who had come to claim His bride, Israel (cf. Isaiah 54:5-8; Isaiah 62:5; Jeremiah 2:2; Hosea 2:19-20; Hosea 2:23; Ezekiel 16). His disciples were His friends who rejoiced at this prospect with Him. Therefore to compel them to fast was inappropriate. Thus Jesus rebuked His questioners. However, Jesus implied that the bridegroom would die. This was one of Jesus" early intimations of His death. Then His disciples would fast. They probably did this after His crucifixion but before His resurrection. They also do it after His ascension and before His return to the earth (cf. John 16:16-24). [source][source][source]