The accomplishment of God's promises is a pledge or assurance that he will also fulfil his threatenings; both of them depending upon the same ground, the faithfulness of God.
Related Commentaries of Joshua 23:15
Joshua 23:15
15 Therefore it shall come to pass, that as all good things are come upon you, which the LORD your God promised you; so shall the LORD bring upon you all evil things, until he have destroyed you from off this good land which the LORD your God hath given you.