Why does Parshat VaYakhel repeat so much that has already been said in Parshat Terumah? Many lines from the first aliyot of each parsha are identical. A common theory is that Parshat Terumah represents the “blueprint” of the Mishkan (Tabernacle) that Moses learned when he was on Mount Sinai for 40 days and 40 nights. Parshat VaYakhel, in contrast, represents the reality of building the Mishkan. The Ishbitzer Rebbe in his book Mei HaShiloach mentions that the 72 elders (6 from each tribe) made shinuim, changes, when building the Mishkan because of constraints.
Often our blueprint represents our greatest vision for the reality. However, there are noticeable differences between what we intend and what we achieve. The place I have seen this most in my life is with the births of my daughters Ariela and Leora. We have all sorts of hopes and dreams for our children, a blueprint laid out, yet we know that the people they will become are different from the people we envisioned-and that is great! My hope and prayer for my daughters is that they continue to construct their own, independent reality, with the guidance from our blueprint, but that their reality will be even more beautiful than we could have envisioned, just as the Mishkan, God’s home, upon its completion was even more wonderous upon its completion than in its blueprint in Parshat Terumah. May our hopes, dreams and what we desire (R’tzei) from God become actualized-to a greater degree than we could have imagined.
 Mei HaShiloach Sefer Shemot, Volume I, Parshat VaYakhel, ד”ה ויקהל משה