Vedic Metre in its Historical Development c12.s3.44

c12.s3.44

168. Before suffixes we find long vowels always before *-van*, but short vowels regularly before *-mant*, *-vant*, except where the ending is *-yāvant* (-*īāvant*): long and short vowels almost indifferently in derivatives in *-yánt*, *-yá*, *-yú* and the corresponding verbs in *-y*.