וַיִּשְׁאַ֨ל דָּוִ֤ד בַּֽיהוָה֙ לֵאמֹ֔ר הַאֶֽעֱלֶה֙ אֶל־פְּלִשְׁתִּ֔ים הֲתִתְּנֵ֖ם בְּיָדִ֑י וַיֹּ֨אמֶר יְהוָ֤ה אֶל־דָּוִד֙ עֲלֵ֔ה כִּֽי־נָתֹ֥ן אֶתֵּ֛ן אֶת־הַפְּלִשְׁתִּ֖ים בְּיָדֶֽךָ׃
And David inquired of the LORD, saying: ‘Shall I go up against the Philistines? wilt Thou deliver them into my hand?’ And the LORD said unto David: ‘Go up; for I will certainly deliver the Philistines into thy hand.’
Read halakhic rulings (Jewish law) on II Samuel 5:19: and classical halakhic sources.