1 Kings 18:41

And Elijah said unto Ahab, get thee up
From the brook and valley where the execution of the prophets had been made; either up to his chariot, or to the tent or pavilion erected on the side of the mount, where the whole scene of things was transacted;

eat and drink;
which he had no leisure for all the day, from the time of the morning sacrifice to the evening sacrifice, which was taken up in attending to the issue of the several sacrifices; but now he is bid to eat and refresh himself, and that in token of joy and gladness, as became him, both for the honour of the true God, which had been abundantly confirmed, and for the near approach of rain, of which he assures him:

for there is a sound of abundance of rain;
the wind perhaps began to rise, and blow pretty briskly, which was a sign of it ^F6; besides, according to the Tyrian annals ^F7, there were loud claps of thunder at this time, at least when the heavens became very black, as in ( 1 Kings 18:45 ) .