Mahabharata 13.69.3
प्रयत्नं तत्र कुर्वाणास्तस्मात्कूपाज्जलार्थिनःश्रमेण महता युक्तास्तस्मिंस्तोये सुसंवृते
prayatnaṃ tatra kurvāṇāstasmātkūpājjalārthinaḥśrameṇa mahatā yuktāstasmiṃstoye susaṃvṛte
Our plain-language meaning of this verse is waiting for scholar review.
Open in the book