Garudapurana 3.26.104

3.26.104

hrasvaṃ tathā vartulaṃ nīlavarṇaṃ sūkṣmaṃ mukhaṃ mukhacakraṃ suśuddham /
suveṇuyuktaṃ vāsudevābhidheyaṃ dānaṃ kalau durlabhaṃ tasya bhadre //

Small, round, dark blue, with a fine aperture, an aperture-disc that is very pure, / endowed with a beautiful flute, called Vāsudeva; its gift is rare in the Kali age, O auspicious one.