Here "Now" marks a break in the main story line. This gives background information about the Gibeonites. (See: [[rc://en/ta/man/translate/writing-background]])
These two sentences have similar meanings. AT: "What can I do to remove this sin, so that you may bless the people of Yahweh, who inherit his goodness and promises?" (See: [[rc://en/ta/man/translate/figs-parallelism]])