σεαυτοῦ
"of thyself", only in gen., dat. and acc. sg., masc. and fem., Hdt., attic; ἐν σαυτῷ γενοῦ contain thyself, Soph.:—in pl. separated, ὑμῶν αὐτῶν, etc.: and orig. it was separated in sg., as in Hom., who always says σοὶ αὐτῷ, σ᾽ αὐτόν.
An Intermediate Greek-English Lexicon Keyed to Strong's Numbers
σεαυτοῦ
"of thyself", only in gen., dat. and acc. sg., masc. and fem., Hdt., attic; ἐν σαυτῷ γενοῦ contain thyself, Soph.:—in pl. separated, ὑμῶν αὐτῶν, etc.: and orig. it was separated in sg., as in Hom., who always says σοὶ αὐτῷ, σ᾽ αὐτόν.