Some thoughts on this passage:
- The Lord swears by Himself because there is no greater name by which He can take an oath.
- The Lord repeats the covenant blessings here -- numerous descendants, victory over enemies, worldwide blessing -- all resulting from obedience to the covenant demands.
- As far as all nations being blessed, that is an amazing consequence to obedience to God. I wonder if we think enough about the consequences of our own actions, especially as to how others will be affected. Even if our choices are not as dramatic as Abraham's, simple acts of obedience to God's Word can bring great blessings to our own families and the people we interact with every day. Also, I suppose, acts of disobedience would have the same result, only in the opposite direction. That shows me just how important it is to obey God. There is no 'small' sin.