Shiva Purana

siva.sh/siva-purana/uma-samhita/25/43

ऋतोर्विकारभूताश्च गुणास्तत्रैव भामिनि ।। प्रमाणं दक्षिणं प्रोक्तं ज्ञातव्यं प्राणवेदिभिः ।। ४३ ।।

sanskrit

O fair lady, the attributes and the aberrations of the seasons constitute that in the right-hand practices. This shall be known by those who understand the motion of vital airs.

english translation

RtorvikArabhUtAzca guNAstatraiva bhAmini || pramANaM dakSiNaM proktaM jJAtavyaM prANavedibhiH || 43 ||

hk transliteration by Sanscript