अथाध्यात्मम् ।अधरा हनुः पूर्वरूपम् ।उत्तरा हनुरुत्तररूपम् ।वाक्सन्धिः ।जिह्वा सन्धानम् ।इत्यध्यात्मम् ।इतीमा महासँहिताः ।य एवमेता महासँहिता व्याख्याता वेद ।सन्धीयते प्रजया पशुभिः ब्रह्मवर्चसेनान्नाद्येन सुवर्गेण लोकेन ॥ ४ ॥
In plain words
Now with respect to the self. The lower jaw is the prior form, the upper jaw the latter form, speech the junction, the tongue the joiner. So much with respect to the self. These are the great joinings. He who knows these great joinings thus expounded is joined with offspring, with cattle, with the lustre of Brahman, with food to eat, and with the heavenly world.