Why does Herbert advise pip to get Provis out of England in Great Expectations?

The prisoner Provis/Magwitch had been transported (shipped to Australia as punishment for a crime) for a stated number of years. He returned in spite of it and was liable for re-arrest if anyone recognized him and turned him in. He returned for two reasons: first, he wanted to see "his gentleman" Pip; it's revealed that Provis/Magwitch was Pip's benefactor instead of Miss Havisham, as Pip assumed. His second reason was to be avenged on the man (Compeyson) who turned him in originally. Herbert knows that Provis will be arrested and hanged if he's not smuggled out of the country. He is, in fact, caught as Pip is desperately trying to get him to the Continent. Provis is returned to prison but dies before any further punishment can be carried out.