The Transfiguration is included as a Feast Day (liturgical colour: white) on August 6th in the Revised Common Lectionary, presumably as an ecumenical nod to the traditions of the Eastern churches. But it is already included on the last Sunday in Epiphany as well! Since we are reading Matthew this year, we have already read his account, so now we are offered the version recorded by Luke. In case you are preaching on this or thinking about it, here is what I wrote last year on Luke’s version.
There some important things to note in relation to the account of the Transfiguration in Luke 9.28-36 as we think about preaching on it.
All three Synoptic accounts place this immediately after Peter’s confession of Jesus at Caesarea Philippi, where Jesus then starts to talk about his betrayal and death. They seem to want us to hold these two truths together: that the Son of Man is one who is humble and obedient even to death; and yet he is also the one spoken of in Daniel 7 where he comes to the Ancient of Days and receives a kingdom that will never end. Both of these are true about Jesus, and both must be held together. This is made clear by the final saying of Jesus in the previous pericope (section):
Amen I say to you, some who are standing here will not taste death before they see the the kingdom of God (Luke 9.27).
Note that Mark adds ‘with power’ in his parallel (Mark 9.1), and Matthew uses the phrase ‘the Son of Man coming in his kingdom’ (Matt 16.28); this is the erchomenos language of Matt 24 referring to the Son of Man coming to the Ancient of Days, not the parousia language of Jesus’ return at the End, so we can see that all three understand Jesus’ comment as a reference to his exaltation and ascension, and the giving of the Spirit at Pentecost followed by the preaching of the gospel.