《魏书·列传·卷四十三》
又《礼内则》称： 子事父母，夜晚鸡开始鸣叫时，梳洗插笄。 
又《礼》、《内则》称： 子事父母，鸡初鸣，栉纚笄总。 
Also the Rituals: Domestic Rules state: When a son serves his parents, when the rooster crows at night, he combs his hair and inserts the 笄.