Lexical Definition

‎סָכַל‎ çâkal (saw-kal') be foolish H:V
for ‎כָּסַל‎

do (make, play the, turn into) fool(-ish, -ishly, -ishness).

1) to be foolish, be a fool
1a) (Piel) to make foolish, turn into foolishness
1b) (Niphal) to act or do foolishly
1c) (Hiphil) to do foolishly, play the fool

Usage: 7 forms in 8 verses
Form Translated As     In Verse(s)
סַכֶּל make foolish 2Sam.15.31
נִסְכָּ֑לְתָּ you have acted foolishly 1Sam.13.13
נִסְכַּ֣לְתָּ you have acted foolishly 2Chr.16.9
נִסְכַּ֖לְתִּי I have acted foolishly 2Sam.24.101Chr.21.8
יְשַׂכֵּֽל he makes foolish Isa.44.25
הִסְכַּ֥לְתָּֽ you have behaved foolishly Gen.31.28
הִסְכַּ֛לְתִּי I have behaved foolishly 1Sam.26.21

Brown-Driver-Briggs

[‎סָכַל‎] verb be foolish, or a fool, usually in moral or spititual sense (Syriac Aph`el act foolishly; foolish, etc., ᵑ7 ‎סְכַל‎ derived species, act foolishly; ‎סַכְלָא‎ fool; Christian-Palestinian Aramaic , Aph`el = ἁμαρτάνω, also derivatives SchwIdioticon 62; Assyrian saklu, perhaps foolish, DlHWB 498; Aramaic ‎סְכַל‎ know, be intelligent, cause to understand, etc. (derived species), compare ‎שׂכל‎; MeiChrest. Targ. derives both these opposite meanings from Arabic form, likeness. Gerber178 thinks Hebrew verb denominative); —

Piel Imperfect ‎יְסַכֵּל‎ Isa 44:25, Imperative ‎סַכֶּלנָֿא‎ 2Sam 15:31, make foolish, turn into foolishness. Niph`al Perfect 2 masculine singular ‎נִסְכַּלְתָּ‎ 2Chr 16:9 ‎נִסְכָּ֑לְתָּ‎ 1Sam 13:13 1 singular ‎נִסְכַּלְתִּי‎ 2Sam 24:10 = 1Chr 21:8, act or do foolishly. Hiph`il Perfect 2 masculine singular ‎הִסְכַּלְתָּ‎ Gen 31:28 (E), 1 singular ‎הִסְכַּלְתִּי‎ 1Sam 26:21, do foolishly, play the fool.

Brown-Driver-Briggs References

Book Refs
Genesis 31:28
1 Samuel 13:13 · 26:21
2 Samuel 15:31 · 24:10
1 Chronicles 21:8
2 Chronicles 16:9
Isaiah 44:25