Matteo 6:7

A lesson in regard to the form of prayer: But when ye pray, use not vain repetitions, as the heathen do; for they think that they shall be heard for their much speaking.

The chief characteristic of the prayers in heathen worship is a gabbling or babbling, a repetition without end of the same forma of words, 1 Kings 18:26; Acts 19:34. Such customs were familiar to the Jews as well as to the Galileans, on account of the mixed population and the presence of strangers in their midst.

The idea supporting such meaningless repetitions seems to have been that the very flood of words should argue for the sincerity of the worshiper and practically weary the gods into complying with their wishes.