Isaiah — Chapter 58
Synopsis Capitis
Synopsis: True fasting contrasted with hypocritical external fasting. 'Is not this the fast that I choose: to loose the bonds of wickedness, to undo the straps of the yoke, to let the oppressed go free?' (v.6). The promises attached to true fasting (v.8-12): 'your light shall break forth like the dawn' and 'you shall be like a watered garden.' The Sabbath passage (v.13-14) — true observance vs. mechanical observance. Lapide reads this as a key text on the relationship of interior religion to external practice.
Verse 6
Nonne hoc est magis jejunium quod elegi? Dissolve colligationes impietatis
Is not this the fast that I choose: to loose the bonds of wickedness, to undo the straps of the yoke, to let the oppressed go free, and to break every yoke? To share your bread with the hungry, and bring the homeless poor into your house. The definition of true religion: not external mortification alone but justice and charity. Lapide: exterior fasting without interior conversion and active charity is hypocrisy. The 'yoke' to be broken = first the yoke of sin (interior liberation), then the yoke of social oppression (exterior liberation). Applied to Lenten penance: the Church's fast must be accompanied by almsgiving (the corporal works of mercy) to be authentic. This verse is the charter of Christian social teaching.
Verse 8
Tunc erumpet quasi mane lumen tuum
Then shall your light break forth like the dawn, and your healing shall spring up speedily. The sevenfold reward of true fasting and charity: light (divine illumination), healing, divine rearguard protection, answered prayer, divine guidance, watered garden, renewing of ancient foundations. Lapide: these rewards are primarily spiritual — the soul that practices justice and charity is flooded with divine light (understanding of Scripture, spiritual joy), healed of disordered passions, guided by the Lord through difficult decisions, and becomes like a spring that never fails.