וַיִּקַּ֨ח שְׁמוּאֵ֜ל אֶת־קֶ֣רֶן הַשֶּׁ֗מֶן וַיִּמְשַׁ֣ח אֹתוֹ֮ בְּקֶ֣רֶב אֶחָיו֒ וַתִּצְלַ֤ח רֽוּחַ־יְהוָה֙ אֶל־דָּוִ֔ד מֵהַיּ֥וֹם הַה֖וּא וָמָ֑עְלָה וַיָּ֣קָם שְׁמוּאֵ֔ל וַיֵּ֖לֶךְ הָרָמָֽתָה׃ (ס)
Then Samuel took the horn of oil, and anointed him in the midst of his brethren; and the spirit of the LORD came mightily upon David from that day forward. So Samuel rose up, and went to Ramah.
Read kabbalistic (mystical) interpretation of I Samuel 16:13: and classical mystical sources.