Why do you rub dumplings on the winter solstice?

The night before the winter solstice is the longest night in a year. Why? Because this night, every household grinds rice and rubs glutinous rice balls, and the rubbed glutinous rice balls can only be eaten by everyone after the early morning of the winter solstice, while the children are greedy and can't eat the rubbed glutinous rice balls, and they can't sleep, looking forward to the dawn, waiting for a good "heart" and the night is long. When the world is old and the night is long, the dawn appears in the East, and the glutinous rice balls also complete the mission of ancestor worship.