Here "the orphan" represents orphans in general. Job is describing how he truly treated orphans. Alternate translation: "because even when I was young I took care of orphans like a father" (See: [[rc://en/ta/man/translate/figs-genericnoun]])
The phrase "But I have done none of those things" is understood from the context. Alternate translation: "But I have done none of those things, because from my youth" (See: [[rc://en/ta/man/translate/figs-explicit]])
Job is describing how he truly treated widows. With the phrase "from my own mother's womb" he uses exaggeration to emphasize that he did this all his life. Alternate translation: "all my life I have guided the orphan's mother, a widow" or "all my life I have guided widows" (See: [[rc://en/ta/man/translate/figs-hyperbole]])