1 Samuel 27:12

וַיֹּאמֶר אָכִישׁ אַל־פְּשַׁטְתֶּם הַיּוֹם וַיֹּאמֶר דָּוִד עַל־נֶגֶב יְהוּדָה וְעַל־נֶגֶב הַיַּרְחְמְאֵלִי וְאֶל־נֶגֶב הַקֵּינִֽי

And Achish said: ‘Whither have ye made a raid to-day?’ And David said: ‘Against the South of Judah, and against the South of the Jerahmeelites, and against the South of the Kenites.’

וְאִישׁ וְאִשָּׁה לֹֽא־יְחַיֶּה דָוִד לְהָבִיא גַת לֵאמֹר פֶּן־יַגִּדוּ עָלֵינוּ לֵאמֹר כֹּֽה־עָשָׂה דָוִד וְכֹה מִשְׁפָּטוֹ כָּל־הַיָּמִים אֲשֶׁר יָשַׁב בִּשְׂדֵה פְלִשְׁתִּֽים

And David left neither man nor woman alive, to bring them to Gath, saying: ‘Lest they should tell on us, saying: So did David, and so hath been his manner all the while he hath dwelt in the country of the Philistines.’

וַֽיְהִי בַּיָּמִים הָהֵם וַיִּקְבְּצוּ פְלִשְׁתִּים אֶת־מַֽחֲנֵיהֶם לַצָּבָא לְהִלָּחֵם בְּיִשְׂרָאֵל וַיֹּאמֶר אָכִישׁ אֶל־דָּוִד יָדֹעַ תֵּדַע כִּי אִתִּי תֵּצֵא בַֽמַּחֲנֶה אַתָּה וַאֲנָשֶֽׁיךָ

And it came to pass in those days, that the Philistines gathered their hosts together for warfare, to fight with Israel. And Achish said unto David: ‘Know thou assuredly, that thou shalt go out with me in the host, thou and thy men.’

וַיֹּאמֶר דָּוִד אֶל־אָכִישׁ לָכֵן אַתָּה תֵדַע אֵת אֲשֶׁר־יַעֲשֶׂה עַבְדֶּךָ וַיֹּאמֶר אָכִישׁ אֶל־דָּוִד לָכֵן שֹׁמֵר לְרֹאשִׁי אֲשִֽׂימְךָ כָּל־הַיָּמִֽים

And David said to Achish: ‘Therefore thou shalt know what thy servant will do.’ And Achish said to David: ‘Therefore will I make thee keeper of my head for ever.’ .