四分律刪繁補闕行事鈔 1.147

1.147

戒場上者，由前外界不成，謂言在內者得。此二界同在自然，不同一相，是別界故。

On the ordination platform: because the previous exterior boundary is not accomplished, it is thought that those inside are acceptable. These two boundaries are both within the natural [boundary], but do not share the same characteristics; because it is a separate boundary.