During his forty day retreat in the Church of St. Charles in Castellazzo (Italy) St. Paul of the Cross writes:
Friday, 27th December, 1720 – Feast of Saint John, Apostle and Evangelist
Through the infinite goodness of God, I enjoyed great repose and tenderness, especially at Holy Communion. Through infused understanding and deepest consolation of the Spirit, I enjoyed a certain spiritual rest, mingled with the sufferings of the Redeemer, in which my soul takes delight. There was a mingling of love and sorrow. On this point I cannot give a clearer explanation because it is impossible to explain. During the time I was serving Mass and while I beheld Jesus in the Blessed Sacrament, I kept asking him to send the seraph to pierce me through with darts of love. This comes from the loving impulses which the Infinite Mercy imparts to the heart. I also asked him to allow me to quench my thirst for his love by allowing me to drink from the infinite font of his most Sacred Heart, but this last happened to me at Holy Communion.