*mVṭṭ-at- - bed (Kogan 2015: 298)

PCS

*nṭw - to stretch (down) (Kogan 2015: 298)

Ugaritic

mṭh - bed or downwards (DUL 604)

for the meaning “downwards” cf. Pho. mṭ ‘what is below’ and Hbr. máṭṭā ‘beneath, downwards’ ; for the meaning “bed” cf. Hbr. miṭṭā ‘couch, bed’ (HALOT 573).

Hebrew

miṭṭā - couch, bed (HALOT 573)