Luke 9:33

33 As the two men were departing from Him, Peter said to Jesus, "Master, it's good for us to be here! Let us make three tabernacles: one for You, one for Moses, and one for Elijah"-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 They appeared in glory and were speaking of His death, which He was about to accomplish in Jerusalem.

32 Peter and those with him were in a deep sleep, and when they became fully awake, they saw His glory and the two men who were standing with Him.

33 As the two men were departing from Him, Peter said to Jesus, "Master, it's good for us to be here! Let us make three tabernacles: one for You, one for Moses, and one for Elijah"-not knowing what he said.

34 While he was saying this, a cloud appeared and overshadowed them. They became afraid as they entered the cloud.

35 Then a voice came from the cloud, saying: This is My Son, the Chosen One; listen to Him!