“vindicate.” The Hebrew word is “judge,” but here it means “judge in favor of,” or “vindicate.” A number of English translations have “vindicate” (cp. CSB; ESV; NASB; NIV2011; NRSV; RSV).
“none remaining to help.” There have to be people remaining, or else there would be no one for God to have compassion on. The JPS Torah Commentary gives evidence that the Hebrew idiom “has to do with power or help and means ‘neither supporter nor helper,’ as the Peshitta and the Talmud render it.” Especially in the context, which says, “their power is gone,” it makes sense that, rather than being no people at all, there were no people who could help.
“slave or free.” The Hebrew is unclear. Different scholars have different opinions about exactly what that means, and so the English versions differ in their translations. Given the culture, and the fact that slaves were restrained or confined by their circumstances while free people were “loose,” the translation “slave or free” made sense. However, the more usual meaning of the second noun, often translated “free” more generally means “abandoned,” “forsaken.” The verse may mean that no one was left to help Israel, not even the slaves or abandoned people were left to help Israel.