四分律比丘含注戒本 3.122

3.122

不犯者：或有病；為人打，舉手遮；或惡獸、擔刺人來，舉手遮；或浮渡渠；以手招喚伴。

There is no offence: if one is ill; if one is beaten by someone and raises a hand to block it; if a vicious beast or someone carrying sharp stakes comes and one raises a hand to block it; if one swims across a ditch; or if one beckons a companion with one's hand.