四分比丘戒本疏 2.42

2.42

第十掘地戒。謂壞潤濕堪生草木之地。准《僧祇律》壞如蚊脚犯提。若須堀，使淨人，云：「看是知是。」若直教云堀是者，犯提也。

Tenth: the precept against digging the earth. This refers to damaging earth that is moist and capable of growing grass and trees. According to the Mahāsāṃghika-vinaya, damaging an amount like a mosquito's leg incurs a prāyaścittika. If digging is necessary, one should instruct a kappiya-kāraka, saying: 'Look at this, know this.' If one directly tells him, 'Dig this,' it incurs a prāyaścittika.