In 2 Samuel 7, we learn that God's Covenant with David includes great blessings. As we read through these, we can be nodding our heads in agreement - they are truly great blessings. And then we arrive at v. 14, which speaks of chastening. The subject hasn't really changed, however. God blesses His people by chastening them. God loves them enough to put them through grevious chastening that they might emerge out on the other end purified, for His glory.