וַיִּבְקְעוּ֩ שְׁלֹ֨שֶׁת הַגִּבֹּרִ֜ים בְּמַחֲנֵ֣ה פְלִשְׁתִּ֗ים וַיִּֽשְׁאֲבוּ־מַ֙יִם֙ מִבֹּ֤אר בֵּֽית־לֶ֙חֶם֙ אֲשֶׁ֣ר בַּשַּׁ֔עַר וַיִּשְׂא֖וּ וַיָּבִ֣אוּ אֶל־דָּוִ֑ד וְלֹ֤א אָבָה֙ לִשְׁתּוֹתָ֔ם וַיַּסֵּ֥ךְ אֹתָ֖ם לַֽיהוָֽה׃
And the three mighty men broke through the host of the Philistines, and drew water out of the well of Beth-lehem, that was by the gate, and took it, and brought it to David; but he would not drink thereof, but poured it out unto the LORD.
Read midrashic interpretation of II Samuel 23:16: and classical rabbinic exegesis.