Yōga Sūtra 3.35

हृदये चित्तसंवित्।

hr̥dayē cittasaṁvit।

[हृदये चित्त संवित्।
hr̥dayē = on the heart; citta = consciousness; saṁvit = covering;]

(By samyama) on the heart, one understands the coverings of Chitta.