Luke 9:33

33 When Moses and Elijah had left, Peter said to Jesus, "Master, this is a great moment! Let's build three memorials: one for you, one for Moses, and one for Elijah." He blurted this out without thinking.

Luke 9:33 Meaning and Commentary

Luke 9:33

And it came to pass, as they departed from him
That is, as Moses and Elias departed from Christ; or "when they began to depart", as the Syriac version renders it; or "would depart", as the Arabic and Persic versions; seemed desirous of going, or made some signal or other by which the disciples perceived they were about to go; for, as yet, they were not gone;

Peter said unto Jesus, master, it is good for us to be here, let us
make three tabernacles, one for thee, and one for Moses, and one for
Elias; (See Gill on Matthew 17:4)

not knowing what he said,
nor "what to say", as Mark observes, being in a surprise, and not in a situation to consider and weigh things well, whether what he said was right and proper, or not; (See Gill on Matthew 17:4)

Luke 9:33 In-Context

31 and what a glorious appearance they made! They talked over his exodus, the one Jesus was about to complete in Jerusalem.

32 Meanwhile, Peter and those with him were slumped over in sleep. When they came to, rubbing their eyes, they saw Jesus in his glory and the two men standing with him.

33 When Moses and Elijah had left, Peter said to Jesus, "Master, this is a great moment! Let's build three memorials: one for you, one for Moses, and one for Elijah." He blurted this out without thinking.

34 While he was babbling on like this, a light-radiant cloud enveloped them. As they found themselves buried in the cloud, they became deeply aware of God.

35 Then there was a voice out of the cloud: "This is my Son, the Chosen! Listen to him."