In the contest of the conversation between Nawab and Harouni, Nawab's comments in lines 43-52 mainly serve to
- flatter Harouni by mentioning how vast his lands are
- notify Harouni that Nawab intends to quit his job tending the tube well
- boast to Harouni about how competent reliable Nawab is
- emphasize Nawab's diligence and loyalty to Harouni