Commentary for Exodus 27:6

ועשית בדים למזבח, בדי עצי שטים , “you are to construct staves for the altar, staves made of shittim wood.” It would have seemed more appropriate for the Torah to write: ועשית בדים למזבח עצי שטים, without repeating the word בדים once more. Alternately, the Torah could have written: ועשית למזבח בדי עצי שטים, which would have been the shortest way to express the same instruction, just as the Torah did in connection with the ark where the Torah wrote: ועשית בדי עצי שטים. Why this peculiar wording then? It was to allude to the fact that these staves were to be extremely long-lasting (compare Kings I 8,8). There was a miracle involved in all this as our sages (Tanchuma Terumah 17) have mentioned that G’d said that “in the future these staves would be 487 years ‘long’”. The idea was that from the time of the original construction of the Tabernacle until the dedication of Solomon’s Temple 487 years later no other staves would be used to transport the altar.