Cannot understand (SB cantos 1 - 3)

Expressions researched:
"can not be understood" |"can not understand" |"can't understand" |"cannot be understood" |"cannot understand"

SB Canto 1

SB 1.2.20, Purport:

One has to surpass the brahminical stage and reach the vasudeva stage to understand the Personality of Godhead Kṛṣṇa. The science of the Personality of Godhead is the subject matter for study by the postgraduate students in the spiritual line. Foolish men, or men with a poor fund of knowledge, do not understand the Supreme Lord, and they interpret Kṛṣṇa according to their respective whims. The fact is, however, that one cannot understand the science of the Personality of Godhead unless one is freed from the contamination of the material modes, even up to the stage of a brāhmaṇa. When a qualified brāhmaṇa factually becomes a Vaiṣṇava, in the enlivened state of liberation he can know what is actually the Personality of Godhead.