Natyashastra
चतुर्भिस्तु भवेन्मात्रा त्रिमात्रं वस्तुसञ्ज्ञितम् । त्रिवस्तु द्विकलं ज्ञेयं भवेत्पातो विधीयते ॥ २२२॥
Four ॥ Kalās॥ will make one Mātrā and the Vastu will consist of three Mātrās. ॥ Each of॥ these three Vastus will consist of two Kalās. This is the rule of Pāda in Pāta.
english translation
caturbhistu bhavenmAtrA trimAtraM vastusaJjJitam । trivastu dvikalaM jJeyaM bhavetpAto vidhIyate ॥ 222॥
hk transliteration by Sanscript