aul. Only here, and Exodus 21:6.
for ever. Figure of speech Synecdoche (of the Whole), App-6, whole time put for part of time.
Related Commentaries of Deuteronomy 15:17
Deuteronomy 15:17
17 Then thou shalt take an aul, and thrust it through his ear unto the door, and he shall be thy servant for ever. And also unto thy maidservant thou shalt do likewise.