וַיִּשְׁמַ֤ע אֱלִיאָב֙ אָחִ֣יו הַגָּד֔וֹל בְּדַבְּר֖וֹ אֶל־הָאֲנָשִׁ֑ים וַיִּֽחַר־אַף֩ אֱלִיאָ֨ב בְּדָוִ֜ד וַיֹּ֣אמֶר ׀ לָמָּה־זֶּ֣ה יָרַ֗דְתָּ וְעַל־מִ֨י נָטַ֜שְׁתָּ מְעַ֨ט הַצֹּ֤אן הָהֵ֙נָּה֙ בַּמִּדְבָּ֔ר אֲנִ֧י יָדַ֣עְתִּי אֶת־זְדֹנְךָ֗ וְאֵת֙ רֹ֣עַ לְבָבֶ֔ךָ כִּ֗י לְמַ֛עַן רְא֥וֹת הַמִּלְחָמָ֖ה יָרָֽדְתָּ׃
And Eliab his eldest brother heard when he spoke unto the men; and Eliab’s anger was kindled against David, and he said: ‘Why art thou come down? and with whom hast thou left those few sheep in the wilderness? I know thy presumptuousness, and the naughtiness of thy heart; for thou art come down that thou mightest see the battle.’
Read halakhic rulings (Jewish law) on I Samuel 17:28: and classical halakhic sources.