'Rock' in the Bible

he is like a man building a house, who digged and went deep, and laid a foundation upon the rock: and when a flood arose, the stream brake against that house, and could not shake it: because it had been well builded.

And other fell on the rock; and as soon as it grew, it withered away, because it had no moisture.

And those on the rock are they who, when they have heard, receive the word with joy; and these have no root, who for a while believe, and in time of temptation fall away.