John Gill Commentary 1 Kings 18:36

"And it came to pass at the time of the offering of the [evening] oblation, that Elijah the prophet came near, and said, O Jehovah, the God of Abraham, of Isaac, and of Israel, let it be known this day that thou art God in Israel, and that I am thy servant, and that I have done all these things at thy word." — 1 Kings 18:36 (ASV)

And it came to pass, at the time of the offering of the
evening sacrifice
Which the people of God at Jerusalem were now attending to:

that Elijah the prophet came near ;
to the altar he had built, and on which he had laid the sacrifice:

and said ;
in prayer to God:

Lord God of Abraham, Isaac, and Jacob ;
the covenant God of the ancestors of his people, though they had now so fully departed from him:

let it be known this day that you are God in Israel ;
and that there is no other:

and that I am your servant ;
a true worshipper of him, and his faithful prophet and minister:

and that I have done all these things at your word ;
restrained rain from the earth for some years past, and now had convened Israel, and the false prophets, together, that by a visible sign from heaven it might be known who was the true God; all which he did not of himself, but by the impulse, direction, and, commandment of the Lord.