Luke 9:33

33 And it came to pass that, as they were departing from him, Peter saith to Jesus: Master, it is good for us to be here: and let us make three tabernacles, one for thee, and one for Moses; and one for Elias: not knowing what he said.

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 Appearing in majesty. And they spoke of his decease that he should accomplish in Jerusalem.

32 But Peter and they that were with him were heavy with sleep. And waking, they saw his glory and the two men that stood with him.

33 And it came to pass that, as they were departing from him, Peter saith to Jesus: Master, it is good for us to be here: and let us make three tabernacles, one for thee, and one for Moses; and one for Elias: not knowing what he said.

34 And as he spoke these things, there came a cloud and overshadowed them. And they were afraid when they entered into the cloud.

35 And a voice came out of the cloud; saying: This is my beloved son. Hear him.