A form of Lokopacāravinaya (formal rules of modesty);
to attend the Ācārya (preceptor) by sitting in his vicinity for obtaining knowledge.
'abbhāsavattiyaṃ'ti pratyāsattivarttitvaṃ, śrutādyarthinā hi ācāryādisamīpe āsitavyamityarthaḥ.
(Sthā 7.137 Vṛ Pa 388)