SB 4.8.52

evaṁ bhagavato rūpaṁ
 subhadraṁ dhyāyato manaḥ
nirvṛtyā parayā tūrṇaṁ
 sampannaṁ na nivartate
Synonyms: 
evam — thus; bhagavataḥ — of the Supreme Personality of Godhead; rūpam — form; su-bhadram — very auspicious; dhyāyataḥ — meditating; manaḥ — the mind; nirvṛtyā — being freed from all material contamination; parayā — transcendental; tūrṇam — very soon; sampannam — being enriched; na — never; nivartate — come down.
Translation: 
One who meditates in this way, concentrating his mind upon the always auspicious form of the Lord, is very soon freed from all material contamination, and he does not come down from meditation upon the Lord.
Purport: 

This fixed meditation is called samādhi, or trance. A person constantly engaged in the transcendental loving service of the Lord cannot be deviated from meditating on the form of the Lord, as described herein. The arcana-mārga, or the devotional path prescribed in the Pañcarātra system of devotional service for worshiping the Deity in the temple, makes the devotee think constantly of the Lord; that is samādhi, or trance. One who practices in this way cannot deviate from the service of the Lord, and that makes him perfect in the mission of human life.