O Lord, you have mercy upon all.
Take away from me my sins,
and mercifully kindle in me
the fire of your Holy Spirit.
Take away from me the heart of stone,
and give me a heart of flesh,
a heart to love and adore you,
a heart to delight in you,
to follow and enjoy you, for Christ’s sake. Amen.
Source: Ambrose, d. 397
Source of this version: Modified from https://anglicanprayer.wordpress.com/2010/03/04/lent-prayers-st-ambrose-give-me-a-heart-of-flesh/
Also quoted in The One Year Book of Personal Prayer, © 1991 Tyndale House Publishers (May 17)