TT #1 · Parshas Shemini · Aliyah 1 · Passuk 1
Chabad.org — Vayikra Chapter 9 with Rashi
וַֽיְהִי֙ בַּיּ֣וֹם הַשְּׁמִינִ֔י קָרָ֣א מֹשֶׁ֔ה לְאַהֲרֹ֖ן וּלְבָנָ֑יו וּלְזִקְנֵ֖י יִשְׂרָאֵֽל׃Megillah 10b.
E-Daf.com — Megillah 10b (Tsurras Hadaf)
English: “And it was on the eighth day.” That day was a joy before the Holy One, blessed be He, like the day on which heaven and earth were created. Here it says “and it was on the eighth day,” and there it says “and it was evening and it was morning,” linking the two by the repeated expression vayehi.
Gezeirah shavah — the repeated expression vayehi links the eighth day of the Mishkan to the day of Creation.
The eighth day was a day of joy before the Holy One, comparable to the day on which heaven and earth were created; the derivation links the repeated word ויהי.