A couple of YS's are "interesting" from a linguistic POV. Some of those are, IMO, II 47
sthira-sukham aasanam. and II 48 prayatna-shaithilyaananta-samaapattibhyaam. 47 is usually translated to something like Posture (should be) steady and comfortable (Taimni). The original suutra, "of course", doesn't contain anything to suggest "should be". Word-for-word it's simply steady-comfortable posture (or stuff). 48 seems somewhat elliptic, even for a suutra. Seems rather rare, that a suutra consist merely of the, we guess, ablative dual form of a dvandva compound, whose components in turn seem to consist of tat-puruSa compounds (prayatna-shaithilya, ananta-samaapatti) - especially when a connector(?), usually 'ca' or 'vaa' is "lacking". Why are we *guessing*, that the inflectional case is *ablative* dual? Well, in Sanskrit dual inflection instrumental, dative and ablative cases are identical in form, ending with -bhyaam. So, it depends on the context which one of those cases is in question (...aaarrgghh). What gives? Well, if we combine those two suutras, the result is a "typical" suutra where the cause, or whatever, of the topic is given in the ablative case. Voilaarilaarilaa! Thus, it would seem that for some reason PataƱjali has "divided" a suutra that would make rather perfect sense without being divided: sthira-sukham aasanaM prayatna-shaithilyaananta-samaapattibhyaam, which might be translated for instance to: Posture (becomes) steady and comfortable by relaxation of effort and meditation on the Endless (applying Taimni's translation for 'ananta-samaapatti'). -- But of course we might be all wrong with that... (Now it's time to go see, whether Benefon Inc has finally gone bankrupt...)