Bṛhadāraṇyaka Upaniṣad 6.4.9

Sa yam ikkhet kamayeta meti tasyam artham nishtaya mukhena mukham sandhayopastham asya abhimrisya gaped angadangat sambhavasi hridayad adhi gayase, sa tvam angakashayo 'si digdhaviddham iva madayemam amum mayiti.