Matthew Poole and continuators on 1 Chronicles 28:2

2 Then David the king stood up upon his feet , and said, Hear me, my brethren , and my people. As for me, I had in mine heart to build an house of rest for the ark of the covenant of the LORD, and for the foot-stool of our God, and had made ready for the building:

Partly out of Reverence to God and his Word, which was the Matter of the following Discourse; and partly out of Respect to this great and honourable Assembly.

So he calls the Princes and chief Rulers, both because they had a Share with him, though under him, in the Government; and in compliance with the Divine Command, that the King should not be lifted up above his Brethren, Deut. 17. 20.

A place where it might be fixed, and no more removed from place to place, as it had been.

Which is here put expositively, for by the Foot stool &c. he means the Ark.