To recommit is to make a promise again, like when you recommit yourself to serving your Girl Scout troop by selling loads of cookies. It can also mean to carry out a crime for a subsequent time (something a Girl Scout would never do).
When you recommit to cleaning your guinea pig's cage daily, you swear that you'll get back on a regular cleaning schedule. When you and your friends paint graffiti on your neighbor's garage two days in a row, you recommit the crime of vandalism. The prefix re- tells you that this verb is describing repeated or recurring action.