So Ahab went up to eat and to drink. And Elijah went up to the top of Carmel; and he cast himself down upon the earth, and put his face between his knees,

Wesley's Notes

18:42 The top of Carmel - Where he might pour out his prayers unto God; and whence he might look towards the sea. He had a large prospect of the sea from hence. The sailors at this day call it cape Carmel. Between his knees - That is, bowed his head so low, that it touched his knees; thus abasing himself in the sense of his own meanness, now God had thus honoured him.

Jamieson-Fausset-Brown Bible Commentary

42. Ahab went up to eat and to drink-Ahab, kept in painful excitement by the agonizing scene, had eaten nothing all the day. He was recommended to refresh himself without a moment's delay; and, while the king was thus occupied, the prophet, far from taking rest, was absorbed in prayer for the fulfilment of the promise (1Ki 18:1).

put his face between his knees-a posture of earnest supplication still used.

Matthew Henry's Concise Commentary

18:41-46 Israel, being so far reformed as to acknowledge the Lord to be God, and to consent to the execution of Baal's prophets, was so far accepted, that God poured out blessing upon the land. Elijah long continued praying. Though the answer of our fervent and believing supplications does not come quickly, we must continue earnest in prayer, and not faint or give over. A little cloud at length appeared, which soon overspread the heavens, and watered the earth. Great blessings often arise from small beginnings, showers of plenty from a cloud of span long. Let us never despise the day of small things, but hope and wait for great things from it. From what small beginnings have great matters arisen! It is thus in all the gracious proceedings of God with the soul. Scarcely to be perceived are the first workings of his Spirit in the heart, which grow up at last to the wonder of men, and applause of angels. Elijah hastened Ahab home, and attended him. God will strengthen his people for every service to which his commandments and providence call them. The awful displays of Divine justice and holiness dismay the sinner, extort confessions, and dispose to outward obedience while the impression lasts; but the view of these, with mercy, love, and truth in Christ Jesus, is needful to draw the soul to self-abasement, trust, and love. The Holy Spirit employs both in the conversion of sinners; when sinners are impressed with Divine truths, they should be exhorted to set about the duties to which the Saviour calls his disciples.