The following is from Amy Carmichael of Dohnavur by Frank Houghton.
When the children of Dohnavur were really difficult, Amma [Amy)] sometimes told them of a day when she sorely grieved her mother.
I had been very willful and, as you know, the will of a child can be like steel. My mother did not know what to do with me, for I would not give in, and was not at all sorry. So at last she set me upon a green ottoman which was at the foot of the bed, and, perhaps to give me time to think, she said. “I am going out now.” Then she put on her bonnet.
And as she tied the ribbons of her bonnet I watched her hands moving in the dressing-table looking-glass. The table was across the corner of the room opposite the ottoman, so that when she stood with her back to me I could see her reflected in the mirror. And then I found myself looking not at her hands tying on the bonnet, but at her face.
Suddenly something melted inside me. In one moment I was in her arms, soft and sorry and wanting to be good. It was the look on her face, such a grieved look, that was too much for me.
And often since then I have thought that if when we sin we could see the face of the Saviour as in a mirror, we should never have the heart to grieve Him again.