Jamieson, Fausset and Brown on 1 Chronicles 22:6

6. Then he called for Solomon ... and charged him--The earnestness and solemnity of this address creates an impression that it was given a little before the old king's decease. He unfolded his great and long cherished plan, enjoined the building of God's house as a sacred duty on him as his son and successor, and described the resources that were at command for carrying on the work. The vast amount of personal property he had accumulated in the precious metals [1Ch 22:14] must have been spoil taken from the people he had conquered, and the cities he had sacked.