Because Pip feels responsible for having brought Herbert into debt with him, and because Herbert is a dear friend, Pip uses his five hundred pounds to procure Herbert a position from "a worthy young merchant or shipping broker" who is not long established and is in need of a knowledgeable clerk and well as capital.
Between him and me, secret articles were signed of which Herbert was the subject, and I paid him half of my five hundred pounds down, and engaged for sundry other payments: some, to fall due at certain dates out of my income: some contingent on my coming into my property.
Wemmick's fiancee, Miss Skiffins, has her brother conduct the negotiation, with Wemmick quietly in the background. Pip hopes that when he comes into some property, he can use part of that to further help Herbert in his endeavors. However, after Magwitch is revealed as his benefactor, but he dies, Pip finds that he must turn to Miss Havisham to "spare the money to do my friend Herbert a lasting service in life."