釋氏要覽 2.47

2.47

When Buddhists meet and are about to withdraw, they say aloud 'zhenzhong' (take care), just as in the secular custom of this land they say 'ānzhì' (peace and comfort). To say 'zhenzhong' is to instruct them to take good care of themselves. If a junior goes to a senior's place, and the senior elder tells him to sit and receive scripture, upon leaving afterward, he does not say 'zhenzhong'; he merely joins his palms and bows his head to show respect.