וְהָיָ֗ה כְּהַפְנֹת֤וֹ שִׁכְמוֹ֙ לָלֶ֙כֶת֙ מֵעִ֣ם שְׁמוּאֵ֔ל וַיַּהֲפָךְ־ל֥וֹ אֱלֹהִ֖ים לֵ֣ב אַחֵ֑ר וַיָּבֹ֛אוּ כָּל־הָאֹת֥וֹת הָאֵ֖לֶּה בַּיּ֥וֹם הַהֽוּא׃ (ס)
And it was so, that when he had turned his back to go from Samuel, God gave him another heart; and all those signs came to pass that day.
Read kabbalistic (mystical) interpretation of I Samuel 10:9: and classical mystical sources.