104 Saint Bernard takes up the symbolism of the pierced side of the Lord and understands it explicitly as a revelation and outpouring of all of the love of his heart. Through that wound, Christ opens his heart to us and enables us to appropriate the boundless mystery of his love and mercy: “I take from the bowels of the Lord what is lacking to me, for his bowels overflow with mercy through the holes through which they stream. Those who crucified him pierced his hands and feet, they pierced his side with a lance. And through those holes I can taste wild honey and oil from the rocks of flint, that is, I can taste and see that the Lord is good… A lance passed through his soul even to the region of his heart. No longer is he unable to take pity on my weakness. The wounds inflicted on his body have disclosed to us the secrets of his heart; they enable us to contemplate the great mystery of his compassion”.
Source: Dilexit Nos (Vatican.va)