The book of Exodus has a lot of detail. How to make the Tabernacle. How to make the priestly vestments. How do do this and how to do that. And it is all from God, so it is very important. One could read it and just assume it was the "fluff" God used to fill out the middle of the story, or we could remember that everything God does and says has a purpose. God put the details in there on purpose.
I've copied the entirety of Chapter 27 of Exodus below, but let's look first forward to Leviticus 10. In this chapter, two of Aaron's sons get the details wrong. Perhaps they thought it was just "fluff" as well, or maybe they just messed up, but in any event, it didn't go well. And Nadab and Abihu, the sons of Aaron, took either of them his censer, and put fire therein, and put incense thereon, and offered strange fire before the LORD, which he commanded them not. And there went out fire from the LORD, and devoured them, and they died before the LORD. (Lev 10:1-2)
Now we get a lot more grace than that, but we must remember that God really does care about the details. He isn't suggesting we get around to His way of thinking when it is convenient and do it in a manner that meets our needs and wants.
Here's an example from Exodus on the details:
And thou shalt make an altar of shittim wood, five cubits long, and five cubits broad; the altar shall be foursquare: and the height thereof shall be three cubits. And thou shalt make the horns of it upon the four corners thereof: his horns shall be of the same: and thou shalt overlay it with brass. And thou shalt make his pans to receive his ashes, and his shovels, and his basons, and his fleshhooks, and his firepans: all the vessels thereof thou shalt make of brass. And thou shalt make for it a grate of network of brass; and upon the net shalt thou make four brasen rings in the four corners thereof. And thou shalt put it under the compass of the altar beneath, that the net may be even to the midst of the altar. And thou shalt make staves for the altar, staves of shittim wood, and overlay them with brass. And the staves shall be put into the rings, and the staves shall be upon the two sides of the altar, to bear it. Hollow with boards shalt thou make it: as it was shewed thee in the mount, so shall they make it.
And thou shalt make the court of the tabernacle: for the south side southward there shall be hangings for the court of fine twined linen of an hundred cubits long for one side: And the twenty pillars thereof and their twenty sockets shall be of brass; the hooks of the pillars and their fillets shall be of silver. And likewise for the north side in length there shall be hangings of an hundred cubits long, and his twenty pillars and their twenty sockets of brass; the hooks of the pillars and their fillets of silver. And for the breadth of the court on the west side shall be hangings of fifty cubits: their pillars ten, and their sockets ten. And the breadth of the court on the east side eastward shall be fifty cubits. The hangings of one side of the gate shall be fifteen cubits: their pillars three, and their sockets three. And on the other side shall be hangings fifteen cubits: their pillars three, and their sockets three. And for the gate of the court shall be an hanging of twenty cubits, of blue, and purple, and scarlet, and fine twined linen, wrought with needlework: and their pillars shall be four, and their sockets four. All the pillars round about the court shall be filleted with silver; their hooks shall be of silver, and their sockets of brass. The length of the court shall be an hundred cubits, and the breadth fifty every where, and the height five cubits of fine twined linen, and their sockets of brass. All the vessels of the tabernacle in all the service thereof, and all the pins thereof, and all the pins of the court, shall be of brass.
And thou shalt command the children of Israel, that they bring thee pure oil olive beaten for the light, to cause the lamp to burn always. In the tabernacle of the congregation without the vail, which is before the testimony, Aaron and his sons shall order it from evening to morning before the LORD: it shall be a statute for ever unto their generations on the behalf of the children of Israel.