The Sunday of the Word of God was instituted by Pope Francis in the Apostolic Letter, 'Aperuit illis'. It occurs on the 3rd Sunday in Ordinary Time.
Pope Francis released the Apostolic Letter at the Basilica of Saint John Lateran on 30th September 2019, the liturgical Memorial of Saint Jerome. 2020 marks the 1600th anniversary of the saint's death.
'At the conclusion of the Extraordinary Jubilee of Mercy, I proposed setting aside “a Sunday given over entirely to the word of God, so as to appreciate the inexhaustible riches contained in that constant dialogue between the Lord and his people” (Misericordia et Misera, 7). Devoting a specific Sunday of the liturgical year to the word of God can enable the Church to experience anew how the risen Lord opens up for us the treasury of his word and enables us to proclaim its unfathomable riches before the world.' (Aperuit illis, 2)
'Consequently, I hereby declare that the Third Sunday in Ordinary Time is to be devoted to the celebration, study and dissemination of the word of God. This Sunday of the Word of God will thus be a fitting part of that time of the year when we are encouraged to strengthen our bonds with the Jewish people and to pray for Christian unity. This is more than a temporal coincidence: the celebration of the Sunday of the Word of God has ecumenical value, since the Scriptures point out, for those who listen, the path to authentic and firm unity.' (Aperuit illis, 3)