Natyashastra
वर्णाश्चत्वार एवाथ स्तम्भेषु विनियोजिताः । आदित्याश्चैव रुद्राश्च स्थिताः स्तम्भान्तरेश्वथ ॥ ८६॥
The four varnas were assigned to the pillars, and the Adityas and Rudras were placed in the spaces between the pillars.
english translation
varNAzcatvAra evAtha stambheSu viniyojitAH । AdityAzcaiva rudrAzca sthitAH stambhAntarezvatha ॥ 86॥
hk transliteration by Sanscript