The Horn of David

How is this Psalm all about the LORD Jesus Christ, the Seed to come? Why is it imperative that we read the Scriptures in context? How does the horn we read about here represent strength and power a picture of Christ? What was the covenant that Christ made with His children? Was there anything that David could look to in his own house to recommend him to the LORD? Why did the LORD ordain horns to be put on the corners of the alter? How is Christ the ‘Horn of David’ representing His Sacrifice? How is Christ the 'Lamp ordained by God', an illustration of Christ as the Eternal Light?