In plain words
One may expound the Vedas and the śāstras and have the learned study them, and study them oneself; one may have those entitled to yajña, yāga and tapas perform them, and perform them oneself; one may urge others to go to the holy places of this earth, and go there oneself; one may teach the noble the siddhis of the eight-limbed yoga, and practise them oneself; but to restrain the body and the senses and hold them still, to turn the mind within and, without ceasing, stand firm with minds in unmoving samādhi: this they cannot do. What misfortune could be greater than this?
Embodiments of Prema!
The Vedas are nothing other than the gathered words of Satya of the great ṛṣis, the seers of the mantras. The in-breath and out-breath of the Paramātma, these are the Vedas. That which proclaims the Satya that stands unshaken in the three worlds and in the three times: that is the Veda. That which, with the welfare of the dwellers of the three worlds in view, brings them Śānti and happiness: that is the Veda.
The Veda was born of the root vit. It is itself the embodiment of Jñāna. That which teaches the right means, whether for gaining what one desires or for keeping away what one does not desire, is the Veda. “Ananto vai vedaḥ”: unbroken and endless as it is, this Veda was hard for men to study. In former times there was only the one Veda. To study it took endless time. All one's time went to waste in study alone, and it became impossible to live it out in practice and in inquiry; seeing this state of things, the revered Vyāsa divided it.
From this matchless Veda he took only some of the ṛks and called that the Ṛgveda, took only the yajuses and called that the Yajurveda, took only the sāmans and called that the Sāmaveda: so he divided it into three.