The two Books of Samuel contain valuable historical material concerning the religious and moral conditions of the period. Samuel is the great prophet-judge who helps to unite the scattered tribes under one king, Saul. The history of the reigns of Saul and David is also recorded.

1 Samuel 20

20:42 And Jonathan said to David, Go in peace, forasmuch as we have sworn both of us in the name of the LORD, saying, The LORD be between me and thee, and between my seed and thy seed for ever. And he arose and departed: and Jonathan went into the city.