David said, Whoever would strike the Jebusites (who held impregnable Jerusalem for 400+ years), let him reach (them). through the water tunnel. 2 Samuel 5:8a
It is when you stop banging on the doors of the stronghold, and begin to enter through the water tunnel (power of the Holy Spirit and the Word) that you will find victory. Ron Daniel

David made the fortress city (Jerusalem) his home and named it "City of David." He developed the city from the outside terraces inward. 2 Samuel 5:9

Just as you would not neglect seeds .planted with the hope that they will bear vegetables and fruits and flowers, so you must attend to and nourish the garden of your becoming. Jean Houston

So David went on and became great, for the Lord God of hosts (all of creation) was with him. 2 Samuel 5:10
Our God has a method in providence by which he can succeed our endeavors beyond our expectation, or can defeat our plans to our confusion and dismay. Charles H. Spurgeon (1834-92) English preacher Baptist

So David knew that the Lord had established him as king over Israel, and that He had exalted His kingdom for the sake of His people Israel. 2 Samuel 5:12

You lack nothing that His grace can't give you. He has allowed you to be here at this time in history to fulfil His special purpose for this generation. You are God’s servant in God’s place at God’s perfect time. Roy Lessin.

Meanwhile, David took more concubines and wives from Jerusalem (continuing to violate the law of God of one man and one woman), 2 Samuel 5:13a

The custom of sinning takes away the sense of it, the course of the world takes away the shame of it. John Owen