In the “Sermon on the Mount,” what did Jesus mean when He Jesus said that a person should not pray as the “heathen” who use “vain repetitions” (Mt 6:7)?

Pagan worship often requires chanting, incantations, and repetitions. With this warning, Jesus was explaining that His disciples should avoid meaningless repetition. God desires sincerity and devotion in prayers not long ritualistic utterances. God is REAL and our words to Him should express our thoughts and hopes. (See: Hos 7:14; Joel 2:12-13)