The Law Code of Parāśara 5.18

Parāśarasmṛti 5.18

ekaviṃśatim ūrubhyāṃ dviśataṃ jānujaṅghayoḥ /
pādāṅgulīṣu ṣaḍ dadyād yajñapātraṃ tato nyaset //