I noted at the time that Luke, unlike Matthew and Mark, says that the Transfiguration happened "about eight days" afterward:
There is some scriptural precedent for eight days being of some importance:
Leviticus 23.39: 39 "On exactly the fifteenth day of the seventh month, when you have gathered in the crops of the land, you shall celebrate the feast of Yahweh for seven days [ἑπτὰ ἡμέρας], with a rest on the first day [τῇ ἡμέρᾳ τῇ πρώτῃ] and a rest on the eighth day [τῇ ἡμέρᾳ τῇ ὀγδόῃ]."
Ezekiel 43.25: 25 "For seven days you shall prepare daily a goat for a sin offering; also a young bull and a ram from the flock, without blemish, shall be prepared. 26 For seven days they shall make atonement for the altar and purify it; so shall they consecrate it. 27 And when they have completed the days, it shall be that on the eighth day and onward, the priests shall offer your burnt offerings on the altar, and your peace offerings; and I will accept you,' declares the Lord God."
But I doubt that these pieces of Mosaic legislation and prophetic reinterpretation comprise the sole and immediate background to the Lucan eight days; Peter does suggest in Luke 9.33 that he and the disciples erect tabernacles for Jesus and his two guests, but I think there is more going on, as well. Indeed, these scriptural passages themselves are probably the result of the same kind of sabbatical speculation upon which I imagine Luke was drawing: to wit, the eighth day of the week (so to speak) is actually the first day of the week again. Eight/eighth is, in this case, an especially symbolic way of saying one/first.
Gnostic texts capitalized on this symbolism, naturally, with their sacred Ogdoad: an eighth sphere located outside the seven spheres governed by the seven known planets (in order from earth, in the Ptolemaic scheme: Moon, Mercury, Venus, Sun, Mars, Jupiter, Saturn).
Resurrection, as the beginning of new life, was also a natural fit for this kind of symbolism; the original creation took six days, with God resting on the seventh, and now it is time for a new creation on the eighth day:
John 20.24-29: 24 But Thomas, one of the twelve, called Didymus, was not with them when Jesus came. 25 The other disciples therefore were saying to him, "We have seen the Lord!" But he said to them, "Unless I shall see in His hands the imprint of the nails, and put my finger into the place of the nails, and put my hand into His side, I will not believe." 26 And after eight days again His disciples were inside, and Thomas with them. Jesus came, the doors having been shut, and stood in their midst, and said, "Peace be with you." 27 Then He said to Thomas, "Reach here your finger, and see My hands; and reach here your hand, and put it into My side; and be not unbelieving, but believing." 28 Thomas answered and said to Him, "My Lord and my God!" 29 Jesus said to him, "Because you have seen Me, have you believed? Blessed are they who did not see, and yet believed."
As noted above, the eighth day of the week is actually the first day of the week, so it is not surprising to find Jesus being raised on a Sunday in the canonical gospels:
Mark 16.2: 2 And very early on the first day of the week, they came to the tomb when the sun had risen.
Mark 16.9: 9 Now after He had risen early on the first day of the week, He first appeared to Mary Magdalene, from whom He had cast out seven demons.
Luke 24.1: 1 But on the first day of the week, at early dawn, they came to the tomb, bringing the spices which they had prepared.
John 20.1: 1 Now on the first day of the week Mary Magdalene came early to the tomb, while it was still dark, and saw the stone already taken away from the tomb.
John 20.19: 19 When therefore it was evening, on that day, the first day of the week, and when the doors were shut where the disciples were, for fear of the Jews, Jesus came and stood in their midst, and said to them, "Peace be with you."
(These gospels have conveniently combined an absolute dating, the first day of the week, with a relative dating, on the third day or after three days.)
Unless I miss my mark, then, some tradent in the Lucan line has selected "eight days" for its symbolic value as representing a resurrection or exaltation (which the Transfiguration event itself symbolizes). This selection would make perfect sense as a substitute for yet another number, six, with (according to my hypothesis) its own symbolic value representing a resurrection from the dead. That the number six once had this value, ex hypothesi, was quickly becoming dated information as the more potent symbolism surrounding the number eight gradually took over.
Ben.