Christmas Eve Gift

This afternoon, the boys and I went to Publix for a HUGE grocery run. As we were checking out, this lady came up behind us. The cashier asked if she could help her, and she looked at me and replied, "I would like to pay $20 of your grocery bill." What? I was so taken back, I couldn't really respond with anything more than "Thank you!" She handed me this card and disappeared. What a nice, generous and completely out of the blue Christmas gift!