四分律比丘含注戒本 2.241

2.241

According to the demarcated boundaries of the various regions, each incurs a fall. In a non-village or wilderness, walking up to ten li incurs a fall. If less than one village, or less than ten li, or walking within a single boundary between multiple villages, as well as the preliminary effort of making an appointment together—in all [such cases it is a] duṣkṛta.