John Gill Commentary Jonah 1:7

"And they said every one to his fellow, Come, and let us cast lots, that we may know for whose cause this evil is upon us. So they cast lots, and the lot fell upon Jonah." — Jonah 1:7 (ASV)

And they said everyone to his fellow That Jonah awoke and rose up, upon the shipmaster's calling to him, is certain; but whether or not he called upon his God is uncertain; perhaps he did: and when his prayer was over, and the storm still continuing, the sailors said one to another, come, and let us cast lots, that we may know for whose cause this evil [is] upon us. They observed something very uncommon and extraordinary in the tempest. All means, both natural and religious, failed to help them. Although they knew they were each sinners, they supposed there must be one notorious sinner among them who had committed some very enormous crime, which had drawn the divine resentment upon them to such a degree. Therefore, they proposed to cast a lot, which was an appeal to the divine Being, in order to find out the guilty person.

That the Heathens used the lot upon occasion is not only manifest from profane writers, but from the sacred Scriptures; as Haman, and other enemies of God's people; and the soldiers that attended the cross of Christ, (Esther 9:24) (Joel 3:3) (Obadiah 1:11) (Matthew 27:35) . Drusius reports, from Xavierus, of some Heathens sailing to Japan, and other places in the East Indies, that they used to carry an idol with them, and by lots inquire of it whither they should go; and whether they should have prosperous winds.

so they cast lots, and the lot fell upon Jonah; through the overruling providence and disposing hand of God, which attended this affair; for, not to inquire whether the use of the lot was lawful or not, or whether performed in that serious and solemn manner as it should be, if used at all; it pleased God to interfere in this matter, to direct it to fall on Jonah, with whom he had a particular concern, being a prophet of his, and having disobeyed his will; see (Proverbs 16:33) . The Syriac version renders it, "the lot of Jonah came up"; that is, the piece of paper, or whatever it was, on which his name was written, was taken up first out of the vessel in which the lots were put.