Gen 6.14-16 (LEB)
Make for yourself an ark of cypress wood; you must make the ark with
rooms, then you must cover it with pitch, inside and outside. And this
is how you must make it: the length of the ark, three hundred cubits;
its width fifty cubits; its height, thirty cubits. You must make a
roof for the ark, and finish it to a cubit above. And as for the door
of the ark, you must put it in its side. You must make it with a
lower, second, and a third deck.
This passage is describing the ark having a single roof (or possibly a single skylight), not a single window. The underlying word, tsohar, is a hapax legomenon and can mean roof or skylight/hatch.
צֹהַר. hapax legomenon Gn 6:16; meaning uncertain, two possibilities: —a.
from Akk. ṣēru (AHw. 1093b; CAD Ṣ: 138) back, top, hinterland, open
country, steppe; Canaanite ṣuʾru, ṣūru back (AHw. 1115a; CAD Ṣ: 261b,
gloss zuḫru, El Amarna letter 232:11; VAB 2:1544 zuḫru); Ug. ẓr
(Gordon Textbook §19:1047; Aistleitner 2378; Driver Myths2 147b) back,
top; Soq. ṭhar over; OSArb. ẓhr (Conti Chrest. 160a) and Arb. ẓahr
back; JArm. *טהרא roof
tt, MHeb. (Mish. Yoma 5:6; Tosefta Yoma 4:2):
roof, with many modern (scholars), including THAT 1:647; perhaps
particularly a gabled roof (:: גָּג flat roof, see Armstrong VT 10
(1960) 328-333; TOB; NRSV; REB: make a roof for the ark;
. —b. from root
צהר: skylight, hatch cf. Akk. nappašu small window, loophole
(Gilgamesh xi:135; AHw. 740; CAD N: 311), so e.g. A. Dillmann Die
Genesis6 (1892) 141; König Wb. 383a, cf. Vulg. fenestra, Tg. nēhōr
opening for light; Sept., Pesh. otherwise. †
Koehler, L., Baumgartner, W., Richardson, M. E. J., & Stamm, J. J. (1994–2000). The Hebrew and Aramaic lexicon of the Old Testament (electronic ed., p. 1008). Leiden: E.J. Brill.