Rasendrapurana 46.65

Rasendrapurāṇa 46.65

rekhābhedāḥ
vajre caturvidhā rekhā budhairevopalakṣyate
savyā cāyuḥpradā jñeyā nāpasavyā śubhapradāḥ
urdhvācāsiprahārāya cchedaśchedāya bandhubhiḥ