Verse 15

विचार्यार्यैः सहालोक्य शास्त्राण्यध्यात्मभावनात् ।सत्तासामान्यनिष्ठत्वं यत्तद्ब्रह्म परं विदुः

In plain words

Having deliberated together with the noble, having examined the śāstras through meditation upon the Self, that state of resting wholly in being-as-such -- this they know as the supreme Brahman.