The utensils of the first Beis ha'Mikdash were built by Shlomo ha'Melech. We find in Divrei ha'Yamim II 4:1 that Shlomo ha'Melech built an altar (known as the Copper Altar, but actually made of stone; see Metzudos, and Malbim in Divrei ha'Yamim, as well as Rashi to Zevachim 60a). Since they were different from the Mishkan both in size and in texture (although the proportions remained the same), Chazal concluded that the Mizbe'ach from the Mishkan was hidden, as it is an object of Kedushah and must be treated with respect after it ceases to be used. This is stated both in Avos d'Rebbi Nasan (41:12) and in the Tosefta in Sotah (13:1), where it also states that the Menorah and Shulchan from the Mishkan were used in the Beis ha'Mikdash as well.

The verse in Divrei ha'Yamim I 28:19 states that David ha'Melech received a prophecy telling him how to build the Mizbe'ach as well as other holy utensils, since the concept of "v'Chen Ta'asu" (that it should be like the Mishkan) regarding the Beis ha'Mikdash refers only to the building itself and not to the utensils, which may be different, and the prophecy delineated to him the differences. This would explain the disparity between the two types of utensils.

Yoel Domb