One day a certain nun visited Saint Justin Popovich in his cell to offer him some watermelon, which he received with gratitude.
The nun left, but curiosity overtook her and she looked through his keyhole to see if he would eat it.
All of a sudden she saw him drop ashes on the watermelon before eating it.
For days she was troubled by this action of the Saint, to the point where she was unable to bear it anymore and approached him to ask why he did that.
He replied: "My child, I did not want the taste of the fruit to become sweeter than my sweet Jesus."