John Gill Commentary 1 Kings 18:23

"Let them therefore give us two bullocks; and let them choose one bullock for themselves, and cut it in pieces, and lay it on the wood, and put no fire under; and I will dress the other bullock, and lay it on the wood, and put no fire under." — 1 Kings 18:23 (ASV)

Let them therefore give us two bullocks
Who, being so many, were better able to be at the expense of them, and having the king on their party too; though perhaps no more is meant than that two bullocks should be brought thither, and presented before them:

and let them choose one bullock for themselves ;
which of the two they would, if they thought one was any ways preferable to the other, it was at their option to take it:

and cut it in pieces, and lay it on wood ;
as sacrifices usually were:

and put no fire under ;
which was wont to be done for burnt offerings, as this was designed to be:

and I will dress the other bullock ;
by slaying and cutting it in pieces;

and lay it on wood :
as for a burnt offering:

and put no fire under ;
to consume it.