The tops of the mountains were seen — Like little islands appearing above water. They felt ground above forty days before they saw it, according to Dr. Lightfoots's computation, whence he infers that if the waters decreased proportionably, the ark drew eleven cubits in water.
Related Commentaries of Genesis 8:5
Genesis 8:5
5 And the waters decreasedb continually until the tenth month: in the tenth month, on the first day of the month, were the tops of the mountains seen.