parshat Trumah

...The first utensil that Moshe Rabbeinu was commanded to prepare for the Mishkan was the Holy Ark (Aron), in which the Two Tablets were to be placed. That it was first indicates its importance and central role in the dwelling of the Divine Presence in the Mishkan. And in fact, we find that the very presence of the Aron in the Tabernacle and, later, in the Holy Temple, is what bestowed upon them their special status...

Why does the Torah refer to "the boards," as if we know which boards it is talking about? No boards have yet been mentioned! Furthermore, regarding none of the other utensils in the Mishkan is "the" mentioned; instead it says, "You shall make a menorah… a covering for the tent," etc. Why then are the boards singled out?