Matthew 11:30

For my yoke is sweet, &c. For though, in regard of our weak nature, it be a very heavy yoke, yet the grace of God renders it easy and light, because our Lord himself helps us to bear it, according to that of the prophet Osee, (Chap. xi, ver. 4) I will be unto them as he that takes the yoke from off their head. St. Bernard says, that our Saviour sweetens by the spiritual unction of his grace, all the crosses, penances, and mortifications of religious souls. St. Augustine owns that before he knew the power of grace, he could never comprehend what charity was, nor believe that any one was able to practice it; but the grace of God renders all things easy. (Rodriguez, On Mortification. Chap. xix.)