וְקָרָ֥אתָ לְיִשַׁ֖י בַּזָּ֑בַח וְאָֽנֹכִ֗י אוֹדִֽיעֲךָ֙ אֵ֣ת אֲשֶֽׁר־תַּעֲשֶׂ֔ה וּמָשַׁחְתָּ֣ לִ֔י אֵ֥ת אֲשֶׁר־אֹמַ֖ר אֵלֶֽיךָ׃
And call Jesse to the sacrifice, and I will tell thee what thou shalt do; and thou shalt anoint unto Me him whom I name unto thee.’
Read Kabbalistic (mystical) interpretations of I Samuel 16:3: Zohar and classical Jewish mystical sources, free online.