Yājñavalkya Śikṣā 51

51

udāttaṃ bhruvi pātavyam pracaṃ nāsāgra eva ca
hṛtpradeśe'nudāttaṃ ca tiryagjātyādikāḥ svarāḥ

The high-pitched accent is to be cast onto the eyebrow, and the monotone accent right at the tip of the nose; / and the low-pitched accent in the region of the heart; the natural circumflex and following accents are oblique.