 नदी निलयना स्सर्पा नदीकुटिलगामिनः।तिषठ्न्त्यावृत्य पन्थानं ततो दुःखतरं वनम्।।। 
 The serpents that live in and move like meandering rivers always obstruct  the paths. Therefore, living in the forest is tremendously difficult. 