BT Pes 31a(22) : כי היכי דמשתעבדנא לכו לדידכו, הכי משתעבדנא ליה לבעל חוב דאבוכו‏ : just as I am indebted to you for things that are yours (var.: your father), so I am indebted to your father's creditor
See the entire entry for šˁbd vb. to enslave