Here’s what the GILH says about readings during Lent, Triduum, and Eastertime:
150. During Lent the readings for the first year are passages from Deuteronomy and the Letter to the Hebrews. Those for the second year review the history of salvation from Exodus, Leviticus, and Numbers. The Letter to the Hebrews interprets the Old Covenant in the light of the paschal mystery of Christ.
First, we get a healthy dose of the Torah, with the Christian seasoning of the Letter to the Hebrews.
A passage from the same letter, on Christ’s sacrifice (Heb 9:11-28), is read on Good Friday; another, on the Lord’s rest (Heb 4:1-16), is read on Holy Saturday. On the other days of Holy Week the readings in Year I are the third and fourth Songs of the Servant of the Lord and extracts from Lamentations; in Year II the prophet Jeremiah is read, as a type of Christ in his passion.
Lamentations and Jeremiah are always good choices for Holy Week.
151. During the Easter season, apart from the First and Second Sundays of Easter and the solemnities of the Ascension and Pentecost, there are the traditional readings from the First Letter of Peter, the Book of Revelation, and the Letters of John (for Year 1), and from the Acts of the Apostles (for Year II).
Natural choices for the Fifty Days.