"her yavam shall come upon her": whether unwittingly, (thinking her to be a different woman), wantonly, (intending illicit intercourse), constrainedly, or wittingly — even if she is unwitting and he wanton or he unwitting and she wanton, (he acquires her as a wife).
(Instead bf being written) "and he shall take" (it is written) "and he shall take her"; (instead of) "and he shall perform yibum," (it is written) "and he shall perform yibum (with) her" — to exclude (from yibum) co-wives (tzaroth) and arayoth (illicit relations) — whence it was ruled: Fifteen women exempt (from yibum) their co-wives and the co-wives of their co-wives, etc.