In the fourth aliyah Betzalel makes the altar of the burnt offerings. He makes the wash basin out of copper, from the mirrors of the women. At first, Moshe didn't want to use these mirrors because they represented the womens' vanity in adorning themselves, but G-d treasured them more than anything else because the women used these mirrors to attract their husbands when they were fatigued in their slavery in Egypt. These lavers were to be used in the Sotah ceremony to make peace between a husband and wife. The Alter Rebbe - Rabbi Schneur Zalman of Liadi - explains that the offerings for the Mishkan included gold, silver, and copper, but nothing sparkled except for the mirrors presented by the women.

Although, these lavers were the last articles of the Mishkan to be made, they were nonetheless the first articles to be used at the starting of every sanctuary service for the washing of the Kohanim.

The fourth aliyah continues into Parshat Pekudai, and gives an accounting of all the precious material used in the construction of the Mishkan, its vessels, and the clothes of the Kohanim.

The count of men over twenty years old is also given and is 603,550.