Mark 4:38 (BSB)

But Jesus was in the stern, sleeping on the cushion. So they woke Him and said, “Teacher, don’t You care that we are perishing?”

From Mark 4. Also in the ESV.

Commentary on Mark 4:38

• Matthew Henry (Presbyterian), Matthew Henry's Complete Commentary on Mark 4:35-41: This miracle which Christ wrought for the relief of his disciples, in stilling the storm, we had before (Mat 8:23, etc.); but it is here more fully related. Observe, 1. It was the same day that he had preached out of a ship, when the even was come, Mar 4:35.
• Adam Clarke (Methodist), Clarke's Commentary on the Bible on Mark 4:38: On a pillow - Προσκεφαλαιον probably means a little bed, or hammock, such as are common in small vessels. I have seen several in small packets, or passage boats, not a great deal larger than a bolster.