John Gill Commentary 1 Kings 8:5

"And king Solomon and all the congregation of Israel, that were assembled unto him, were with him before the ark, sacrificing sheep and oxen, that could not be counted nor numbered for multitude." — 1 Kings 8:5 (ASV)

And King Solomon, and all the congregation of Israel, that were
assembled together
On this solemn occasion:

were with him before the ark ;
while it was in the court of the priests, before it was carried into the most holy place:

sacrificing sheep and oxen, that could not be told nor numbered for
multitude ;
the phrase seems to be hyperbolical, and designed to denote a great number.