"You owe God a penny, and He will not accept a pearl from you in its place."

"You owe God a penny, and He will not accept a pearl from you in its place.  Having lost chastity, do not allow fornication to remain in its place and give alms because of it:  God will not accept them, for in place of sanctification He requires sanctification....
     "Saint Ephraim said, 'In summertime, do not struggle against the scorching heat in winter clothing.'  Let each man reap by means that oppose the iniquity he has sown.  Every disease is cured with its own remedies.  And you, who are overcome with envy, why do you battle against sleep?"

     Saint Isaac the Syrian, Homily 5/42-43.  The ascetical homilies of Saint Isaac the Syrian, rev. 2nd ed., trans. from the Greek and Syriac by the Holy Transfiguration Monastery (Boston, 2011), 156-157.  Cf. Mystic treatises by Isaac of Nineveh translated from Bedjan’s Syriac text with an introduction and registers by A. J. Wensink (Amsterdam, 1923), 43-44/63.