SAHM providing daycare-child hits my kids!

I have been providing daycare for well over 6 months for a little boy. My kids are ages 2 and 4. The boy I watch is almost 2.5 and only recently, for the last 2 weeks constantly hits and pushes my kids over toys, space, etc. I am trying time outs, redirection, positive reinforcement, using his words, separation, ..nothing is working. It is exhausting. I need the income though. Parents say this is not a problem elsewhere, but he does not spend as much time anywhere else. He is with me 30 hrs week. Help! I do not want to dismiss him or give up on the situation. I am hoping he grows out of it when he becomes more verbal, however, it may be months.