Matthew 6:7

7 And when you pray, do not keep on babbling like pagans, for they think they will be heard because of their many words.

Read Matthew 6:7 Using Other Translations

But when ye pray, use not vain repetitions, as the heathen do: for they think that they shall be heard for their much speaking.
"And when you pray, do not heap up empty phrases as the Gentiles do, for they think that they will be heard for their many words.
“When you pray, don’t babble on and on as people of other religions do. They think their prayers are answered merely by repeating their words again and again.