Exodus 38:21
אֵלֶּה פְקוּדֵי הַמִּשְׁכָּן מִשְׁכַּן הָעֵדֻת אֲשֶׁר פֻּקַּד עַל פִּי מֹשֶׁה עֲבֹדַת הַלְוִיִּם בְּיַד אִיתָמָר בֶּן אַהֲרֹן הַכֹּהֵן
These are the accounts of the tabernacle, the tabernacle of testimony, as rendered according to the commandment of Moses, for the service of the Levites, by the hand of Itamar, the son of Aaron the priest.
When speaking of the Mishkan, why does the Torah call it “the tabernacle, the tabernacle of testimony,” repeating the word “Mishkan” (Tabernacle)? Rashi cites the Midrash Tanchuma that this is an allusion to the first two Temples, which were destroyed because of our sins.