四分戒本疏卷第一．第二．第三 3.106

3.106

擊攊比丘戒第五十三　事雖是輕過容至重。人之喜為特。宜須禁故所以制　別緣有五。一是比丘。二作惱亂意。三手脚十指。四無緣。若眠觸令覺行來誤觸等不犯故。五觸著即犯　此戒因六群中一人擊攊十七群中一人。乃至令命終。比丘舉過。佛便呵制戒。

The fifty-third precept on tickling a bhikṣu. Although the matter is light, the fault can easily become extremely grave. It is something people are especially fond of doing and should properly be prohibited, which is why it was instituted. The specific conditions are five: 1. It is a bhikṣu; 2. Having the intention to perturb; 3. The ten fingers of hands or feet; 4. Absence of a cause—for if touching someone asleep to awaken him, or touching by mistake when coming and going, there is no offense; 5. Touching immediately constitutes the offense. This precept was instituted because one among the group of six tickled one among the group of seventeen, even causing him to lose his life. Bhikṣus pointed out the fault, and the Buddha then rebuked them and instituted the precept.