And, behold, there arose a great tempest in the sea, insomuch that the ship was covered with the waves: but he was asleep.

People's New Testament

8:24 There arose a great tempest in the sea. Mark says, A great storm (Mr 4:37); Luke, There came down a storm of wind (Lu 8:23); the word used by Matthew implies a tornado. The Greek word seismos denotes a sudden and violent gust of wind, such as frequently bursts on the lake. All travelers describe the storms as very sudden and violent caused by the cold air that rushes down from the mountains into the heated depression of the lake.

Wesley's Notes

8:24 The ship was covered - So man's extremity is God's opportunity.

Matthew Henry's Concise Commentary

8:23-27 It is a comfort to those who go down to the sea in ships, and are often in perils there, to reflect that they have a Saviour to trust in and pray to, who knows what it is to be on the water, and to be in storms there. Those who are passing with Christ over the ocean of this world, must expect storms. His human nature, like to ours in every thing but sin, was wearied, and he slept at this time to try the faith of his disciples. They, in their fear, came to their Master. Thus is it in a soul; when lusts and temptations are swelling and raging, and God is, as it were, asleep to it, this brings it to the brink of despair. Then it cries for a word from his mouth, Lord Jesus, keep not silence to me, or I am undone. Many that have true faith, are weak in it. Christ's disciples are apt to be disquieted with fears in a stormy day; to torment themselves that things are bad with them, and with dismal thoughts that they will be worse. Great storms of doubt and fear in the soul, under the power of the spirit of bondage, sometimes end in a wonderful calm, created and spoken by the Spirit of adoption. They were astonished. They never saw a storm so turned at once into a perfect calm. He that can do this, can do any thing, which encourages confidence and comfort in him, in the most stormy day, within or without, Isa 26:4.