[Edited by Ellopos from Wikipedia articles.]
Occasionally referred to as 1 Baruch, the book is named after Baruch ben Neriah, Jeremiah’s scribe, its purported author. It contains reflections on the theology and history of Israel, discussions of wisdom, and addresses to residents of Jerusalem and the Diaspora. Some scholars propose that it was written during or shortly after the period of the Maccabees.
Although the earliest known manuscripts of Baruch are in Greek, there is linguistic evidence that the beginning of Baruch (1:1-3:8) was originally translated from a Semitic language.
Although not in the Hebrew Bible, it is found in the Septuagint and in the Vulgate Bible, Eritrean/Ethiopian Orthodox Bible and also in Theodotion’s version. It is grouped with the prophetical books which also include Isaiah, Jeremiah, Lamentations, Ezekiel, Daniel, and the Twelve Minor Prophets. In the Vulgate, the King James Bible Apocrypha, and many other versions, the Letter of Jeremiah is appended to the end of the Book of Baruch as a sixth chapter; in the Septuagint and Orthodox Bibles chapter 6 is usually counted as a separate book, called the Letter or Epistle of Jeremiah.
Athanasius, Cyril of Jerusalem, Epiphanius of Salamis and Pope Innocent I listed the Book of Baruch as canonical.
The Synod of Laodicea (in 364) declared Baruch canonical. The same happened with the Synod of Hippo (in 393), followed by the Council of Carthage (397) and the Council of Carthage (419). Later, Augustine of Hippo (C. 397 AD) would confirm in his book On Christian Doctrine (Book II, Chapter 8) the canonicity of the book of Baruch.
The Decretum Gelasianum which is a work written by an anonymous scholar between 519 and 553 contains a list of books of Scripture presented as having been declared canonical by the Council of Rome under Pope Damasus I, bishop of Rome 366-383. This list mentions the book of Baruch as a part of the Old Testament Canon.
In the Catholic Church, Baruch 3:9–38 is used in the liturgy of Holy Saturday during Passiontide in the traditional lectionary of scriptural readings at Mass. A similar selection occurs during the revised liturgy for the Easter Vigil.
Baruch 1:14 – 2:5; 3:1–8 is a liturgical reading within the revised Roman Catholic Breviary for the Twenty-Ninth Week in Ordinary Time, Friday Office of Readings. The subject is the prayer and confession of sin of a penitent people:
Justice is with the Lord, our God; and we today are flushed with shame, we men of Judah and citizens of Jerusalem, that we, with our kings and rulers and priests and prophets, and with our fathers, have sinned in the Lord’s sight and disobeyed him. … And the Lord fulfilled the warning he had uttered against us…. Lord Almighty, … Hear… and have mercy on us, who have sinned against you… (Baruch 1:15–18; 2:1; 3:1–2)
St. Augustine’s reflection, which is paired with this reading, on this occasion speaks of prayer: “[S]ince this [that we pray for] is that peace that surpasses all understanding, even when we ask for it in prayer we do not know how to pray for what is right…”; from there he explains what it means that the Holy Spirit pleads for the saints.