A Stranger's Christmas Gift at the Supermarket- paid it forward

Hello,
Yesterday I was shopping at Hannaford in Essex. My shopping cart was packed full of Christmas meal items. Before loading my goodies on the conveyor belt, I took a quick look behind me and saw a man standing patiently behind his cart. He had far fewer items that would be "eligible" for the Express lane. I invited him to go ahead of me in line. He said " you don't have to do that". I insisted saying " I would be a terrible person if I didn't".
He smiled and said "Merry Christmas". I smiled back at him, with " Merry Christmas".
I was too busy loading my things to notice a most precious gesture from this stranger.
Out of breath, and with an sigh of exhaustion, I finally looked at the cashier, who asked if I knew the man. I said "No". She replied " Because he just left you $100.00 for your groceries".
I was in shock, and I quickly looked around for him, but he was already out of sight.
My bill was $240.00 of which I was only charged $140.00!

I asked the cashier if She knew his name. She told me, but I am unable to locate him to thank him. He may be out of sight but will never be out of mind. And as for me? I will make sure I pay it Forward.
Happy Holidays
NancyD
Update: I have paid it forward by giving out 20.00 to 5 people;
To the crew at the dump site on Morse Rd in Fairfax,
And to someone I know who really needs it.