चिन्तनं वृत्तिरित्युक्तं वर्तते चित्तमाशया ।चित्तवृत्तिमतो ह्याशां त्यक्त्वा निश्चित्ततां व्रज
In plain words
Dwelling-in-thought is called a vṛtti; citta operates by hope. Therefore, abandoning hope, which is the vṛtti of citta, go to the state of no-citta-ness.