mukhatas talu nirbhinnam
tato nana-raso jajñe
jihvaya yo ’dhigamyate
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
From the mouth the palate became manifested, and thereupon the tongue was also generated. After this all the different tastes came into existence so that the tongue can relish them.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
This gradual process of evolution suggests the explanation of the controlling deities (adhidaiva) because Varuna is the controlling deity for all relishable juices. Therefore the mouth becomes the resting place for the tongue, which tastes all the different juices, of which the controlling deity is Varuna. This suggests, therefore, that Varuna was also generated along with the development of the tongue. The tongue and the palate, being instrumental, are adhibhutam, or forms of matter, but the functioning deity, who is a living entity, is adhidaiva, whereas the person undergoing the function is adhyatma. Thus the three categories are also explained as to their birth after the opening of the mouth of the virat-purusa. The four principles mentioned in this verse serve to explain the three main principles, namely the adhyatma, adhidaiva and adhibhutam, as explained before.