肇論新疏 3.309

3.309

經曰：三箭中的，三獸渡河，中渡無異而有淺深之殊者，為力不同故也。

The sūtra says: “Three arrows striking the target, three beasts crossing the river; that there is no difference in the crossing or hitting yet there are distinctions of shallow and deep is because their strengths are not the same.”