Isaiah — Chapter 54
Synopsis Capitis
Synopsis: The song of the barren woman made fruitful — 'Sing, O barren one, who did not bear' (v.1). Paul (Gal 4:27) applies this to the Church of the Gentiles, formerly 'barren' without the covenant, now the fruitful mother of the redeemed. The chapter continues with God's everlasting love for His people (v.7-10: 'with everlasting love I will have compassion on you') and the image of the city rebuilt with precious stones (v.11-12) — a type of the heavenly Jerusalem (Apoc 21).
Verse 1
Laetare, sterilis, quae non paris
Rejoice, O barren one who has not born — the Gentile Church, formerly without covenant and therefore spiritually barren, is called to rejoice because her children will outnumber the children of the Synagogue (the 'married woman,' with the Mosaic covenant). Paul (Gal 4:27) applies this exactly: the Church of Christ is the 'free woman,' and her children by grace are more numerous than the children of the legal covenant. Applied to Mary: some Fathers (Jerome, Ambrose) read the 'barren one' as the Virgin who bore without human intercourse — spiritually fruitful through the divine seed, mother of all the redeemed.
Verse 10
Montes enim commovebuntur et colles tremebunt; misericordia autem mea non recedet a te
For the mountains may depart and the hills be removed, but my steadfast love shall not depart from you, and my covenant of peace shall not be removed. The 'covenant of peace' (foedus pacis) = the New Covenant in Christ's blood, ratified in the Eucharist. Lapide: this is one of Scripture's strongest assurances of the Church's indefectibility — mountains (the most stable features of creation) may move, but God's covenant-love for the Church cannot. Applied to individual souls: the covenant made in baptism is God's irrevocable commitment; even if we falter, God's love does not 'remove itself' — it remains, calling us back.