From raga'. A wink (of the eyes), i.e. A very short space of time -- instant, moment, space, suddenly.
see HEBREW raga'
H7281. rega
רֶ֫גַע noun masculine a moment (Late Hebrew id.;ריגעא ᵑ7 Ecclesiastes 9:12: probably properly a movement, i.e. twinkling, of the eye; compare momentum, i.e. movimentum); — absolute רָ֑נַע ׳ר, Numbers 16:21 +, plural רְגָעִים; —
a. Psalm 30:6 ׳ר בְּאַמּוֺ a moment (passes) in his anger (opposed to ברצונו חיים); Isaiah 54:7 ׳בְּר קָטֹן during a little moment
b. usually in adverb phrases: — (a) as adverb accusative, (a) Exodus 33:5 ׳ר אֶהָד for one moment, so ׳ר alone Isaiah 54:8; repeated Jeremiah 18:7, 9 רֶגַע ֗֗֗ רֶגַע at another moment; . . . at another moment; (β) in a moment, suddenly, Psalm 6:11 רָ֑גַע יֵבשׁוּ יָשׁוּבוּ, 4:20; Isaiah 47:9; Job 34:20. (b) בְּרֶגַע in a moment 21:13 ׳ובר יַחַ֫תּוּ שְׁאוֺל (of a quick and painless death; but see 34:20; Psalm 73:19: Hoffm Buhl Baer Bu Du [compare ᵐ5 ἐν ἀναπαύσει, בְּמַרְגּוֺעָא ᵑ7] take רֶגַע (or read רְגֹעַ) as substantive [√ II. רָגַע] in tranquility, of a peaceful death). So (c) ׳כְּר Numbers 16:21 = 17:10 כְּרָ֑גַע אֶתֵכֶם וַאֲכַלֶּה, Psalm 73:19. (d) ר ׳כְּמוֺ Lamentations 4:6. (e) רָ֑גַע עֲדֵי while a moment lasts Job 20:5. (f) ר ׳כִּמְעַט like the littleness of a moment = for a little moment Isaiah 26:20; Ezra 9:8. (g) plural לִרְגָעִים by moments, at every moment, Isaiah 27:8; Ezekiel 26:16 ל ׳וְחָֽרְדוּ (so 32:10), Job 7:18 ("" לִבְקָרִים).