Reference for Psalms 51:6

לְךָ֤ לְבַדְּךָ֨ ׀ חָטָאתִי֮ וְהָרַ֥ע בְּעֵינֶ֗יךָ עָ֫שִׂ֥יתִי לְ֭מַעַן תִּצְדַּ֥ק בְּדָבְרֶ֗ךָ תִּזְכֶּ֥ה בְשָׁפְטֶֽךָ׃

Against Thee, Thee only, have I sinned, And done that which is evil in Thy sight; That Thou mayest be justified when Thou speakest, And be in the right when Thou judgest.

ספר השרשים