Philo Judaeus De Confusione Linguarum 9

But he who brings his account nearer the truth, has distinguished between the rational and irrational animals, so that he testifies that identity of language belonged to men alone: and this also, as they say, is a fabulous story. And indeed they affirm, that the separation of language into an infinite variety of dialects, which Moses calls the confusion of tongues, was effected as a remedy for sins, in order that men might not be able to co-operate in common for deeds of wickedness through understanding one another; and that they might not, when they were in a manner deprived of all means of communication with one another, be able with united energies to apply themselves to the same actions.