This action-packed portion contains the final instructions for building the Tabernacle. It also relates the events of the Sin of the Golden Calf. Following the sin, Moses pleads with God to maintain His relationship with the Children of Israel as it had been until that point. God commands Moses to carve a new set of tablets and He reiterated highlights of His law to the people. At the end of the portion, Moses finally descends from Mount Sinai, his face aglow with holiness.
The Portion of Ki Tisa

וַיְדַבֵּר יְהֹוָה אֶל־מֹשֶׁה לֵּאמֹר׃ Hashem spoke to Moshe, saying: וְרָאוּ בְנֵי־יִשְׂרָאֵל אֶת־פְּנֵי מֹשֶׁה כִּי קָרַן עוֹר פְּנֵי מֹשֶׁה וְהֵשִׁיב מֹשֶׁה אֶת־הַמַּסְוֶה עַל־פָּנָיו עַד־בֹּאוֹ לְדַבֵּר אִתּוֹ׃ the Israelites would see how radiant the skin of Moshe' face was. Moshe would then put the veil back over his face until he went in to speak with Him.