From the principal service Gospel:

Jesus took with him Peter and James and John, and led them up a high mountain apart, by themselves. And he was transfigured before them, and his clothes became dazzling white, such as no one on earth could bleach them. And there appeared to them Elijah with Moses, who were talking with Jesus. Then Peter said to Jesus, ‘Rabbi, it is good for us to be here; let us make three dwellings, one for you, one for Moses, and one for Elijah.’ He did not know what to say, for they were terrified.
(Mark’s Gospel, chapter 9, verses 2-6, NRSV)

When we don’t know what to say, some say nothing, and some blurt out the first thing that comes into their heads. Peter was one of the second sort – the only reason he had a foot in his mouth so often was that there wasn’t room for both of them. But on this rock, Jesus built his church – Peter’s impetuosity was a key strength, and well worth the occasional embarrassment!

This window is in St. peter’s church, Sheringham, Norfolk