Visuddhimagga VI-38

Saṇṭhānato uddhumātakassa saṇṭhānavaseneva idamassa sīsasaṇṭhānaṃ, idaṃ gīvāsaṇṭhānaṃ, idaṃ hatthasaṇṭhānaṃ, idaṃ udarasaṇṭhānaṃ, idaṃ nābhisaṇṭhānaṃ, idaṃ kaṭisaṇṭhānaṃ, idaṃ ūrusaṇṭhānaṃ, idaṃ jaṅghāsaṇṭhānaṃ, idaṃ pādasaṇṭhānanti vavatthapetabbaṃ.

③「以形」，是只依膨胀的形而确定这是他的头形，这是他的颈形，这是手形，这是腹形，这是脐形，这是腰形，这是股形，这是胫形，这是足形。

Ñ(VI,38): (3) By its shape: he should define it only by the shape of the bloated thus: 'This is the shape of its head, this is the shape of its neck, this is the shape of its hand, this is the shape of its chest, this is the shape of its belly, this is the shape of its navel, this is the shape of its hips, this is the shape of its thigh, this is the shape of its calf, this is the shape of its foot'.