1)
When was the Parshah of the Mishkan taught to Moshe?
1.
Rashi (in Ki Sisa, 31:18): After the sin of rhe Golden Calf. 1
2.
Ramban: Refer to 25:2:1:2.
3.
Oznayim la'Torah: It was said to him when he ascended Har Sinai, when he was informed that Yisrael will leave Har Sinai - that a Mal'ach would accompany them on their journey to Eretz Cana'an. Moshe would no longer need to ascend a mountain to speak with Hashem, because Hashem would travel with them in 'His House', from which He would communicate with him. 2