“keep repeating the same phrases.” The Greek word is battalogeō (#945 βατταλογέω), and it means, use the same words again and again,a “to babble” in the sense of trying to achieve success in prayer by heaping up repetitions.b Williams translates it as “keep on repeating set phrases.”c That is what many religions do, repeat set prayers because “they think that they will be heard for their many words.”
“like the Gentiles do.” Many pagan religions had formulaic prayers that were repeated over and over, or they repeated the names of the gods over and over. God is not swayed by such behavior. He looks on the heart, and the earnestness of the person praying. Simple, heartfelt prayers associated with the circumstances one needs God’s help with are the prayers that God desires.