My translation: He begged his angry friend that they not keep those very pitiful men in the bonds of servitude.
Wheelock: He begged his angry friend not to keep those very pitiful men in the bonds of servitude.
Latin sentence: Petivit ab amico irato ne eos miserrimos in vinculis servitutis tenerent. Should not the last word be teneret? I do not know if this is a typo or not.