וַיָּבֹ֤א דָוִד֙ אֶל־צִ֣קְלַ֔ג וַיְשַׁלַּ֧ח מֵֽהַשָּׁלָ֛ל לְזִקְנֵ֥י יְהוּדָ֖ה לְרֵעֵ֣הוּ לֵאמֹ֑ר הִנֵּ֤ה לָכֶם֙ בְּרָכָ֔ה מִשְּׁלַ֖ל אֹיְבֵ֥י יְהוָֽה׃
And when David came to Ziklag, he sent of the spoil unto the elders of Judah, even to his friends, saying: ‘Behold a present for you of the spoil of the enemies of the LORD’;
Sforno
וחצית את המלקוח, seeing that this war was a war of revenge for something the enemy had done against the people as a whole, the Torah wanted that the principle of ואכלת את אויביך, “you will consume your enemies,” (Deuteronomy 20,14) be fulfilled. Something similar occurred with David and the loot taken from Amalek (Samuel I 30,26) when he distributed loot he personally had captured from the Amalekites.