str - (nip.) to hide oneself; (hip.) to hide
(HALOT 771)
Hebrew
sīṭ - the distance between the tip of the thumb and that of the index finger when held apart, or between the root of the thumb and the tip of the index finger when the former is leaning against the latter
(Jastrow 977)
in ha-ssīṭ
Hebrew
šä - who, which (relative pronoun); that; since
(HALOT 1365)
Rare in the Bible, but typical of later texts.
Compare Pho. š, ˀš and Akk. šu, šāt, šūt, šāt.