There seems to be a saying in Taoism that it does this, but it is not freckle. Is to wipe the first saliva on your face when you get up in the morning. You can Baidu it.

In addition, I also found a piece of information in Baidu: Leng Qian, a health care practitioner in the Ming Dynasty, recorded in "Essentials of Aging": "The color is haggard, the management is excessive, and the work is not detailed. Sit quietly every morning, close your eyes, concentrate, cheer up, wash your internal organs from the inside out, rub your face with your hands seven times, and still apply mouthwash to your face and rub it several times. According to this method, after half a month's travel, the skin is smooth and the appearance is pleasant, much more than usual. 」