כֹּֽה־יַעֲשֶׂה֩ יְהוָ֨ה לִֽיהוֹנָתָ֜ן וְכֹ֣ה יֹסִ֗יף כִּֽי־יֵיטִ֨ב אֶל־אָבִ֤י אֶת־הָֽרָעָה֙ עָלֶ֔יךָ וְגָלִ֙יתִי֙ אֶת־אָזְנֶ֔ךָ וְשִׁלַּחְתִּ֖יךָ וְהָלַכְתָּ֣ לְשָׁל֑וֹם וִיהִ֤י יְהוָה֙ עִמָּ֔ךְ כַּאֲשֶׁ֥ר הָיָ֖ה עִם־אָבִֽי׃
The LORD do so to Jonathan, and more also, should it please my father to do thee evil, if I disclose it not unto thee, and send thee away, that thou mayest go in peace; and the LORD be with thee, as He hath been with my father.
Read midrashic interpretation of I Samuel 20:13: and classical rabbinic exegesis.