Then the mother of God presented Blessed Dominic to Our Lord. “I accept him,” said the Son of God, “he will do very well and zealously all that you have said.” She then introduced Blessed Francis to him, and the Savior approved of him too.
Now blessed Dominic, considering attentively in this vision that companion whom he did not yet know, met him the next day in a church and recognized him, according to what he had seen during the night. He threw his arms around him, and holding him to his heart, he embraced him with a holy kiss, saying, "You are my brother in arms. You will walk with me and no enemy will prevail against us.”
He then told him about his vision, and from that time they had but one heart and one soul in God. And they recommended to their sons that it be the same between them, always, in all love and reverence, and this simple gesture has left on the ocean of ages an indelible wake, and the two begging militias find there the symbol of their eternal covenant. This is the reason why the Patriarch of Preachers has his place among us Franciscans and we also gives us the title of Father.
In Les Fleurs franciscaines (Franciscan Flowers), 2nd series, page 187