Midrasch zu Divrej Hajamim II 4:1

You find that the altar erected by Moses was more precious to the Holy One, blessed be He, than the altar for the burnt offering made by Solomon. Proof of this is that when Solomon built the Temple, he built an altar for the burnt offering, as is said: A thousand burnt offerings did Solomon offer upon that altar (I Kings 3:4). but because he knew that the altar of brass that Moses had erected was more precious to the Holy One, blessed be He, he brought out the brass altar (which Moses had made), as it is said: Moreover, he made an altar of brass, twenty cubits the length thereof (II Chron. 4:1).