Jesus said the harvest was to occur at the end of the age in His generation. This is a real dilemma for the Futurist's views. Jesus spoke another parable about the kingdom of heaven. This is important in light of Matt. Specifically, Jesus was speaking to His disciples of when He would come in the glory of His Father with the holy angels at the end of the age.
Most Bible interpreters think that the disciples wanted to know about the end of the planet.
No argument and case closed. It means the end of the Mosaic Covenant. In this context of Matt. Hopefully this will make sense to you. Our Lord did not mean to teach or imply that after the age ended, He would no longer be with them.