Matsya Purana 180.16

180.16

sthāṇubhūto hyanimiṣaḥ śuṣka kāṣṭhopalopamaḥ.
sanniyamyendriyagrāmamavatiṣṭhata niścalaḥ .. 180.16 ..

On being thus addressed by his father he left his home and relations and went to Kâśî where he devoted himself to rigid asceticism His eyelids did not fall he curbed his passions and stood motionless like a dried up piece of wood or a piece of stone—15-16