Manasara 57.11

57.11

daśāṃśaṃ hṛdayāntaṃ syānnābhyantaṃ ca daśāṅgulam
bhūtāṃśaṃ meḍhrasīmāntaṃ pīṭhāṃśaṃ śuragāyatam

from [the throat] to the chest is ten parts, and to the navel is ten digits; / from [there] to the boundary of the penis is five parts, and the seat is sixteen long;