SB 8.3.12
namah santaya ghoraya
mudhaya guna-dharmine
nirvisesaya samyaya
namo jñana-ghanaya ca
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
I offer my respectful obeisances to Lord Vasudeva, who is all-pervading, to the Lord’s fierce form as Lord Nrsimhadeva, to the Lord’s form as an animal [Lord Varahadeva], to Lord Dattatreya, who preached impersonalism, to Lord Buddha, and to all the other incarnations. I offer my respectful obeisances unto the Lord, who has no material qualities but who accepts the three qualities goodness, passion and ignorance within this material world. I also offer my respectful obeisances unto the impersonal Brahman effulgence.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
In the previous verses it has been described that although the Supreme Personality of Godhead has no material form, He accepts innumerable forms to favor His devotees and kill the demons. As stated in Srimad-Bhagavatam, there are so many incarnations of the Supreme Personality of Godhead that they are like the waves of a river. The waves of a river flow incessantly, and no one can count how many waves there are. Similarly, no one can calculate when and how the different incarnations of the Lord appear according to the necessities of time, place and candidates. The Lord appears perpetually. As Krsna says in Bhagavad-gita (4.7):
yada yada hi dharmasya
glanir bhavati bharata
abhyutthanam adharmasya
tadatmanam srjamy aham
“Whenever and wherever there is a decline in religious practice, O descendant of Bharata, and a predominant rise of irreligion — at that time I descend Myself.” In the material world there is always the possibility of deviation from Krsna consciousness, and therefore Krsna and His devotees always act in various forms to curb such godlessness.
Even impersonalists who stress the knowledge feature of the Supreme Personality of Godhead want to merge in the effulgence of the Lord. Therefore, here the word jñana-ghanaya indicates that for atheists who disbelieve in the form and existence of the Lord, all these various incarnations appear. Since the Lord comes to teach in so many forms, no one can say that there is no God. The word jñana-ghanaya is especially used here to refer to those whose knowledge has become solidified by dint of their searching for the Lord through speculative philosophical understanding. Superficial knowledge is useless for understanding the Supreme Personality of Godhead, but when one’s knowledge becomes extremely intense and deep, one understands Vasudeva (vasudevah sarvam iti sa mahatma sudurlabhah). A jñani attains this stage after many, many births. Therefore the word jñana-ghanaya is used here. The word santaya indicates that Lord Vasudeva is situated in everyone’s heart but does not act with the living entity. Impersonalist jñanis realize Vasudeva when they are fully mature in knowledge (vasudevah sarvam iti sa mahatma sudurlabhah).