These quotes are from Saint Faustina’s diary, written in the 1930s.
The Catholic Church canonized Faustina as a saint in 2000. She was a Polish nun. She is venerated within the Church as the “Apostle of Divine Mercy”.
Throughout her life, Faustina reported having visions of Jesus and conversations with him, of which she wrote in her diary, later published as The Diary of Saint Maria Faustina Kowalska: Divine Mercy in My Soul. Her Diary quoted some of these conversations with Jesus regarding the Divine Mercy devotion. Her diary, accepted by the Catholic Church, has become an international classic among Catholics.