Dickens uses two cases of anaphora near the middle and near the end of Chapter LIV. What are they, and what is Dickens emphasizing with them? (GREAT EXPECTATIONS)

From the text:

"`Dear boy!' he said, putting his arm on my shoulder as he took his seat. `Faithful dear boy, well done. Thankye, thankye!'"

"`If you knowed, dear boy,' he said to me, `what it is to sit here alonger my dear boy and have my smoke, arter having been day by day betwixt four walls, you'd envy me. But you don't know what it is.

`I think I know the delights of freedom,' I answered.

`Ah,' said he, shaking his head gravely. `But you don't know it equal to me. You must have been under lock and key, dear boy, to know it equal to me -- but I ain't a going to be low.'"

"`You see dear boy, when I was over yonder, t'other side the world, I was always a looking to this side; and it come flat to be there, for all I was a growing rich. Everybody knowed Magwitch, and Magwitch could come, and Magwitch could go, and nobody's head would be troubled about him. They ain't so easy concerning me here, dear boy -- wouldn't be, leastwise, if they knowed where I was.'"