एष मानवि ते गर्भं प्रविष्टः कैटभार्दनः ।
अविद्यासंशयग्रन्थिं छित्त्वा गां विचरिष्यति ॥ १८ ॥
esah-the same Supreme Personality of Godhead; manavi-O daughter of Manu; te-your; garbham-womb; pravistah-has entered; kaitabha-ardanah-the killer of the demon Kaitabha; avidya-of ignorance; samsaya-and of doubt; granthim-the knot; chittva-cutting off; gam-the world; vicarisyati-He will travel over.
Lord Brahma then told Devahuti: My dear daughter of Manu, the same Supreme Personality of Godhead who killed the demon Kaitabha is now within your womb. He will cut off all the knots of your ignorance and doubt. Then He will travel all over the world.
Here the word avidya is very significant. Avidya means forgetfulness of one's identity. Every one of us is a spirit soul, but we have forgotten. We think, "I am this body." This is called avidya. Samsaya-granthi means doubtfulness. The knot of doubtfulness is tied when the soul identifies with the material world. That knot is also called ahaṅkara, the junction of matter and spirit. By proper knowledge received from the scriptures in disciplic succession and by proper application of that knowledge, one can free himself from this binding combination of matter and spirit. Brahma assures Devahuti that her son will enlighten her, and after enlightening her He will travel all over the world, distributing the system of saṅkhya philosophy.
The word samsaya means doubtful knowledge. Speculative and pseudo yogic knowledge is all doubtful. At the present moment the so-called yoga system is prosecuted on the understanding that by agitation of the different stations of the bodily construction one can find that he is God. The mental speculators think similarly, but they are all doubtful. Real knowledge is expounded in Bhagavad-gita: "Just become Krsna conscious. Just worship Krsna and become a devotee of Krsna." That is real knowledge, and anyone who follows that system becomes perfect without a doubt.