PS

*bṭḥ - to be confident, at rest (Kogan 2015:510)

Hebrew
bṭḥ - to be confident (HALOT 120)
Jewish Babylonian Aramaic
bṭḥ - to be confident (DJBA 196)

Is rightly considered a Hebraism in DJBA 196.

Arabic
bṭḥ - to spread, to expand, to extend; to throw somebody down upon his face; VII. to lie, to stretch oneself (Lane 216)

May be remotely related.

Jibbali
béṭaḥ - to throw down on the belly (JL 30)

May be remotely related.

Soqotri
ṭábaḥ - to lie on one’s belly (Naumkin et al. 2013a:83; Kogan 2015:510)