Garudapurana 1.209.39

1.209.39

nau nau go 'tikṛtiḥ proktā cchando hyutkṛtirucyate /
vasvīśāśvairmamatanaiḥ syādbhujaṅgavijṛmbhitam //

and na, na, and a heavy syllable; it is declared in the Atikṛti class; and the Utkṛti metre is spoken of. / Bhujaṅgavijṛmbhita has ma, ma, ta, na, [na, ra, sa, and a light and heavy syllable], with [pause at] eight, eleven, and seven.