四分律比丘含注戒本 2.809

2.809

If a bhikṣu makes a robe equal in measure to the Tathāgata's or makes a robe exceeding the measure, it is a prāyaścittika. Herein the measure of the Tathāgata's robe is: nine Sugata spans in length, and six spans in width. This is called the measure of the Tathāgata's robe.