Or HaChaim on Exodus 25:31/אור החיים על שמות כ״ה:ל״א

1 תיעשה המנורה, the Lampstand shall be made. Why did the Torah need to write these words at all? Was it not enough to write: "you shall construct a Lampstand made of gold?" Our sages in Menachot 28 comment that the word תיעשה allows for the fact that if necessary the Lampstand could be constructed of other metals. The passive form of תיעשה rather than תעשה, "you shall make," is justified then, seeing that in Moses' time there was no need to take advantage of the permission to construct the Lampstand of inferior materials.