SB 4.8.51

smayamānam abhidhyāyet
 sānurāgāvalokanam
niyatenaika-bhūtena
 manasā varadarṣabham
Word for word: 
smayamānam — the Lord’s smiling; abhidhyāyet — one should meditate upon Him; sa-anurāga-avalokanam — one who is looking toward the devotees with great affection; niyatena — in this way, regularly; eka-bhūtena — with great attention; manasā — with the mind; vara-da-ṛṣabham — one should meditate upon the greatest bestower of benedictions.
Translation: 
The Lord is always smiling, and the devotee should constantly see the Lord in this form, as He looks very mercifully toward the devotee. In this way the meditator should look toward the Supreme Personality of Godhead, the bestower of all benedictions.
Purport: 

The word niyatena is very significant in this connection, for it indicates that one should execute the meditation practice as stated above. One should not manufacture a way of meditation on the Supreme Personality of Godhead, but should follow the authorized śāstras and personalities. By this prescribed method one can practice concentration upon the Lord until one is so fixed that he remains in trance, thinking always of the form of the Lord. The word used here is eka-bhūtena, which means “with great attention and concentration.” If one concentrates on the descriptions of the bodily features of the Lord, one will never fall down.