Celia told her father, the Duke, that he allowed Rosalind to stay when her father was banished, because he felt guilty of banishing hi own brother, in other words, Duke Frederick allowed Rosalind to stay because of his guilt, i.e. pleasure and remorse
After duke banished Rosliadn his nice.He utter those word's. It sifnif's that now after bansihment she will be able to meet her father in arden and she will be free from here (Duke palace). She is also says it is also said for that beacuse she is bansihed alone ans she has to leave his coz. i.e. celia in palcae.