וַיְצַו֩ אַבְשָׁל֨וֹם אֶת־נְעָרָ֜יו לֵאמֹ֗ר רְא֣וּ נָ֠א כְּט֨וֹב לֵב־אַמְנ֤וֹן בַּיַּ֙יִן֙ וְאָמַרְתִּ֣י אֲלֵיכֶ֔ם הַכּ֧וּ אֶת־אַמְנ֛וֹן וַהֲמִתֶּ֥ם אֹת֖וֹ אַל־תִּירָ֑אוּ הֲל֗וֹא כִּ֤י אָֽנֹכִי֙ צִוִּ֣יתִי אֶתְכֶ֔ם חִזְק֖וּ וִהְי֥וּ לִבְנֵי־חָֽיִל׃
And Absalom commanded his servants, saying: ‘Mark ye now, when Amnon’s heart is merry with wine; and when I say unto you: Smite Amnon, then kill him, fear not; have not I commanded you? be courageous, and be valiant.’
Read halakhic rulings (Jewish law) on II Samuel 13:28: and classical halakhic sources.