וַיֹּ֣אמֶר יוֹאָ֔ב לֹא־כֵ֖ן אֹחִ֣ילָה לְפָנֶ֑יךָ וַיִּקַּח֩ שְׁלֹשָׁ֨ה שְׁבָטִ֜ים בְּכַפּ֗וֹ וַיִּתְקָעֵם֙ בְּלֵ֣ב אַבְשָׁל֔וֹם עוֹדֶ֥נּוּ חַ֖י בְּלֵ֥ב הָאֵלָֽה׃
Then said Joab: ‘I may not tarry thus with thee.’ And he took three darts in his hand, and thrust them through the heart of Absalom, while he was yet alive in the midst of the terebinth.
Read halakhic rulings (Jewish law) on II Samuel 18:14: and classical halakhic sources.