अधर्मे संप्रवृत्तस्त्वं धर्मं च विजिघृक्षसि ।प्रमाणमेतदस्माकं पूर्वं प्रोक्तं महर्षिभिः ॥
In plain words
You have thrown yourself entirely into adharma — and now you want to lay hold of dharma as well. This is what stands as authority for us: it was declared long ago by the great seers.
Close to the Sanskrit
You, fully engaged in adharma, and yet you wish to seize dharma. This is the authority for us, declared formerly by the great seers.