Celebrated on the day after the feast of the Sacred Heart of Jesus, this feast of the universal Church primarily got promoted through the devotions of Saint John Eudes in the 17th century. The New Testament mentions Mary’s heart only twice - Luke 2:19 and 2:51 - which says ‘Mary kept all these things, reflecting on them in her heart.’
The usage of Mary’s heart is symbolic. It is for thinking and decision making - prudent and wise. It reflects the human personality. Many other saints too promoted devotion to the heart of Mary. But it was in the 20th century it came into prominence. It is a special theme of Fatima. In 1942, Pius XII consecrated the world to the Immaculate Heart of Mary and established this feast for the universal Church
\"Your mustard seed is what the Reign of God is about. Your little faith, your little effort is enough. Give your little bit and stand by amazed as you see what God will do with it. Your mustard seed will flourish.\"