It should seem that those shipmen thought that there was somewhat very singular in this storm, and so far they were all led to interpret a divine judgment in it, by this plan of casting lots for the discovery.
Related Commentaries of Jonah 1:7
Jonah 1:7
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.