King James Version (KJV)
And Saul cast a javelin at him to smite him: whereby Jonathan knew that it was determined of his father to slay David.
Modern English
Saul cast his spear at him to strike him. By this Jonathan knew that his father was determined to put David to death.
Hebrew
וַיָּ֨טֶל שָׁא֧וּל אֶֽת־הַחֲנִ֛ית עָלָ֖יו לְהַכֹּת֑וֹ וַיֵּ֙דַע֙ יְה֣וֹנָתָ֔ן כִּֽי־כָ֥לָה הִ֛יא מֵעִ֥ם אָבִ֖יו לְהָמִ֥ית אֶת־דָּוִֽד׃
vayaṭel shaʾvl ʾet-haḥaniyt ʿalayv lhakotvo vayedaʿ yhvonatan kiy-kalah hiyʾ meʿim ʾabiyv lhamiyt ʾet-david