Natyashastra
नौनागरथयानेषु भूमिकाष्ठासनेषु च । सहासनं न दुष्येत गुरूपाध्यायपार्थिवैः ॥ २२७॥
In city carriages and wooden seats, no one should sit alongside the gurus, preceptors, or kings.
english translation
naunAgarathayAneSu bhUmikASThAsaneSu ca । sahAsanaM na duSyeta gurUpAdhyAyapArthivaiH ॥ 227॥
hk transliteration by Sanscript