10:8 thieves and robbers. Any other teachers or leaders (in the immediate context, the scribes and Pharisees, but in the broader context, any other false leaders) who profess to lead people to God are, spiritually speaking, like robbers, who would steal souls away from true saving faith, which is only to be found in Christ.
10:9 go in and out. The Lord Jesus would lead His sheep out of the small fold of the Old Testament (or “old covenant”) into the broader fold of the new covenant, centered on His church instead of on a chosen nation. In another sense, He would lead His sheep “in” for fellowship, rest and training, then “out” for service.