Appeared to him the Seraphim, having six wings, glorious and fiery, flying from heaven

Jan van Eyck

St. Bonaventure:
Francis being indeed a faithful servant and minister of Christ, about the space of two years before he gave back his spirit to heaven, withdrew himself into an high mountain apart, even that mountain which is called Mount Alverno, and began to fast for forty days to the honour of the Archangel Michael. To think of the things above gave him sweeter comfort than beforetime he was wont, and the hot longing for heaven was kindled in him, so that he began to feel that the gifts from above were poured forth upon him in such fulness as he had never felt before. The burning of his desire made his heart rise towards God like the heart of a seraph, and his tender answering love yearned to be changed into the likeness of him who hath so loved us that he was content to bear the Cross. And it was so that one morning early,about the time of the Feast of the Exaltation of the Holy Cross, he was praying upon the side of the mountain, and there appeared to him as it had been one of the Seraphim, having six wings, glorious and fiery, flying to him from heaven. It came therefore very swiftly, and stood in the air, hard by the man of God. He beheld then the appearance thereof that it was not winged only, but crucified also. His hands and feet were stretched forth and nailed to a Cross. Twain of his wings were lifted up and joined one to the other over his head, and twain were stretched forth to fly withal, and with twain he wrapped around his body. When Francis saw it, he was sore amazed, and his soul was filled with sorrow and gladness, for the eyes of him that appeared were full of strange love and tenderness, so that he conceived great rejoicing thereat, but the nailing to the Cross was so exceedingly dreadful, that as he saw it, a sword of sorrow pierced his soul.

Back in the day, this event in salvation history was celebrated by the Universal Church and not thought of as an embarrassment to the modern mind. The stigma of the stigmata would please Francis. Holy Father Francis, pray for us!