大般涅槃經義記 1.55

1.55

二形相分別，聲聞之人執持威儀，形相端嚴，世共尊敬，故列在先；菩薩隨化，身無定准，形儀不整，故列在後。

Second, distinction by outward form: śrāvakas maintain strict deportment, and their forms are dignified and upright, universally revered by the world, so they are listed first; bodhisattvas respond to conditions and teach transformations, their bodies having no fixed standard and their forms and deportment not being uniform, so they are listed later.