John Gill Commentary Acts 27:38

"And when they had eaten enough, they lightened the ship, throwing out the wheat into the sea." — Acts 27:38 (ASV)

And when they had eaten enough
] Were satisfied, having eaten a full meal:

they lightened the ship ;
of its burden, that it might the better carry them to the shore, and that by the following method:

and cast out the wheat into the sea ;
which seems to have been part of the ship's provision; or one part of their lading, which they brought from Egypt, and were carrying to Italy: they had cast out some of the goods of the ship before, and also the tackling of the ship, and now, last of all, the wheat; for what was eatable they reserved till last, not knowing to what extremity they might be reduced.