There is much to ponder in Thomas Boston's A View of the Covenant of Grace. If you feel you should know more of covenant theology than you do then this could be a good place to start, together with his book on the covenant of works. There are disputed issues within Reformed covenant theology on which (of course) Boston takes a particular line (such as the relationship between the covenant of redemption and the covenant of grace). As you read other covenant theologians you will see more of where he is doing this. But he writes with consistsent clarity, vivid directness, and a transparent and challenging concern for the spiritual state of his readers.
Here Boston describes the infinite descent of the Son of God by comparing it to the journey an angel might have taken: ‘the highest angel’s consent to become a worm, is not to be named in one day with the eternal Son of God, the Father’s equal, his consenting to become man: for the distance between the divine nature and the human is infinite; whereas the distance between the angelic nature, and the nature of worms of the earth, is but finite'.