King David boldly, confidently, & courageously prayed that God should do as He has promised. How many times do we do this right after God speaks to us? We wait months or years after to say, ‘God do what You have promised’. King David did so trusting and believing that God was able to do what He had promised. David knew this and so he responded promptly with thanksgiving and with a confirming prayer of faith.
Additionally, David relied on the things God had done before for him and knew that this was a small thing before the sight of God. (Ps. 68:19; 103:1-6). David was truly grateful that God would honor his desire even far beyond what David wanted to do. (2 Sam. 7:18-21). David just wanted to build an edifice; God was talking about blessing His legacy. Talk about exceedingly and abundantly (Ephesians 3:20-21).
It starts with a desire, to which God will then respond with a promise or some kind of answer or directive. We are then to respond with thanksgiving and faith believing that what He said He will do. It may seem to take long but hold on. God is not slack concerning His promises. (2 Peter 3:8-9). As we read further in the Bible, the temple of the Lord was surely built. – Eruore Oboh