Charles Spurgeon Commentary Mark 4:1

"And again he began to teach by the sea side. And there is gathered unto him a very great multitude, so that he entered into a boat, and sat in the sea; and all the multitude were by the sea on the land." — Mark 4:1 (ASV)

You can easily picture that scene: the Master sitting down in the vessel, with a little breathing space of water between himself and the crowd, and then the multitude on the rising bank, standing one above another, and all gazing upon the Teacher who sat down and taught them. It ought to reconcile any of you who have to stand in the crowd here when you remember that the hearers all stood in those days, and only the preacher sat down.