ὑφεῖσα · hypheisa — LSJ
I placed under or secretly, ὑπείσας ἄνδρας (Ion. part.) having set them in ambush, Hdt. 3.126, cf. 6.103; λόχον ὑφείσας Nic.Dam. 55J.: but as (ὑφ-) εἷσα is the augmented aor. of ἑδ- (cf. καθίζω, Att. fut. καθέσω), the part. must be unaugmented, and ὑπέσας, ὑπέσαντες shd. be restored in Hdt. ll. cc., and either ὑφέσας or the later form ὑφίσας [ῐ] (cf. ὑφίζω) in Nic.Dam. l.c.