אָֽנָּ֣ה יְהוָה֮ כִּֽי־אֲנִ֪י עַ֫בְדֶּ֥ךָ אֲֽנִי־עַ֭בְדְּךָ בֶּן־אֲמָתֶ֑ךָ פִּ֝תַּ֗חְתָּ לְמוֹסֵרָֽי׃
Ach, Herr, ich bin dein Knecht, dein Knecht, Sohn deiner Magd, mir hast du meine Bande gelöst.
Rashi on Psalms
Your servant the son of Your maidservant There is no comparison between the training of a slave who was bought in the market and one who was born to a maidservant in the house.
Rashi on Psalms
You loosed my thongs You untied from my neck the bars and the thongs.