From The Mirror of Charity 1.28.85. (ca. 1142)

I think that, without a doubt, the Lord’s sweet yoke gives birth to whatever tranquility, peace, and joy is mine, but whatever toil, fatigue, or sluggishness I have comes from the remnants of worldly concupiscence. For under that yoke, which the prince of Babylon (i.e. confusion) placed upon my unlucky neck, my strength was weakened, my bones (Ps 31:10) were crushed. Although to some extent my bondage was broken, nonetheless not a little weakness lingers from that ancient oppression.

Thus, the serenity of the sweetness which I now sometimes experience is often disturbed, until he who is a propitiation for all my iniquities also heals all my infirmities and, redeeming my life from ruin, crowns me with mercy and compassion, when the perishable puts on the imperishable, and the mortal puts on immortality, then shall come to pass the saying that is written, “Death is swallowed up in victory,” (1 Cor. 15:54; Isa 25:8). In the meantime, I have some consolation from the sweetness of this yoke and not a little struggle against my long-standing weakness.

St. Aelred of Rievaulx (1110-1167) was an English Cistercian monk and spiritual writer who served as abbot of Rievaulx in Yorkshire from 1147 until his death. He wrote several histories and spiritual treatises, as well as On Spiritual Friendship, which draws on Cicero and St. Augustine to describe how true friendship is rooted in fellowship in Christ. The Mirror of Charity, a treatise on the monastic life, was among his earliest works. His feast day is January 12. This translation is from Robert Louis Wilken, ed., Isaiah: Interpreted by Early Christian Medieval Commentators (Grand Rapids, MI: Eerdmans 2007).