He appeared in another form - In a form unlike his ordinary appearance so much so that they did not at first know him. See the notes at Luke 24:13-31. "As they walked and went into the country." To Emmaus, Luke 24:13.

He appeared - unto two of them - These were the two who were going to Emmaus. The whole account is given by Luke, 24:13-34, where see the notes.
Dr. Lightfoot's criticism upon this passage is worthy of notice.
"That, in the verses immediately going before, the discourse is of the two disciples going to Emmaus, is without all controversy. And then how do these things consist with that relation in Luke, who saith, That they two, returning to Jerusalem, found the eleven gathered together, and they that were with them; who said, The Lord is risen indeed, and has appeared to Simon? Luke 24:34. The word λεγοντας, saying, evidently makes those to be the words των ενδεκα, of the eleven, and of those that were gathered together with them; which, when you read the versions, you would scarcely suspect. For when that word is rendered by the Syriac, cad amrin; by the Arabic, wehom yekolon; by the Vulgate, dicentes; by the Italian, dicendo; by the French, disans; by the English, saying; who, I pray, would take it in another sense, than that those two that returned from Emmaus said, The Lord is risen indeed, etc.? But in the original Greek, when it is the accusative case, it is plainly to be referred to the eleven disciples, and those that were together with them; as if they had discoursed among themselves of the appearance made to Peter, either before, or now in the very access of those two coming from Emmaus. And yet, says this our evangelist, that when those two had related the whole business, they gave no credit to them; so that, according to Luke, they believed Christ was risen, and had appeared to Simon, before they told their story; but, according to Mark, they believed it not, no, not when they had told it. The reconciling therefore of the evangelists is to be fetched thence, that those words pronounced by the eleven, Ὁτι ηγερθη ὁ Κυριος οντως, etc., The Lord is risen indeed, etc., do not manifest their absolute confession of the resurrection of Christ, but a conjectural reasoning of the sudden and unexpected return of Peter. I believe that Peter was going with Cleophas into Galilee, and that being moved with the words of Christ, told him by the women, Say to his disciples and Peter, I go before you into Galilee - think with yourself how doubtful Peter was, and how he fluctuated within himself after his threefold denial, and how he gasped to see the Lord again, if he were risen, and to cast himself an humble suppliant at his feet. When therefore he heard these things from the women, (and he had heard it indeed from Christ himself, while he was yet alive, that when he arose he would go before them into Galilee), and when the rest were very little moved with the report of his resurrection, nor as yet stirred from that place, he will try a journey into Galilee, and Alpheus with him; which, when it was well known to the rest, and they saw him return so soon and so unexpectedly - Certainly, say they, the Lord is risen, and hath appeared to Peter, otherwise he had not so soon come back again. And yet, when he and Cleophas open the whole matter, they do not yet believe even them."

(2) After that he appeared in another form unto two of them, as they walked, and went into the country.
(2) Christ appears to two other disciples and at length to the eleven.

After that,.... A little time, or some few hours after, on the selfsame day; see Luke 24:13;
he appeared in another form: it seems to have been the form, or habit of a gardener that he appeared in to Mary; since she thought him to be one, and to be the gardener that belonged to the garden, in which the sepulchre was: but now it was in another form, or habit, that he appeared; very likely in the habit of a Scribe, or doctor; since he took upon him to expound the Scriptures to the persons he appeared to; as also took bread, and blessed it, when at supper with them, Luke 24:27. According to the Jewish canons (m).
"if two persons eat together, and one of them is a Scribe, and the other an unlearned man, , "the Scribe blesses", and the unlearned man is excused.''
This is not to be understood of any change in the shape of his body, or the features of his face; for as soon as their eyes were opened, which had been before held, they knew him perfectly well: whereas, if there had been such an alteration made in him, that he could not have been known for the same, there would have been no need of holding their eyes, that they should not know him, Luke 24:16. This appearance was
unto two of them; one of them was Cleophas, or Alphaeus, which is the same, Luke 24:18; the other is by some (n) thought to be Simon Peter, from what is said in Luke 24:34 though others (o) think it was Nathanael, and others (p) Luke the evangelist, who conceals his own name, when he mentions the other; and some (q) that his name was Ammaon, which perhaps may be through mistake of the place, Emmaus, where they were going, for the name of one of them, and the appearance to them was,
as they walked, and went into the country: to a country village called Emmaus, about sixty furlongs, or seven miles and a half from Jerusalem; see Luke 24:13.
(m) T. Bab. Beracot, fol. 45. 2. (n) Lightfoot, Hor. in. v. 13. & in Luke. xxiv. 13. (o) Epiphan contra Haeres. l. 1. Haeres. 23. (p) Vid. Theophylact. in Luc. xxiv. 13. (q) Ambros in Luc. 12. 49. & 24.

After that he appeared in another form--(compare Luke 24:16).
unto two of them as they walked, and went into the country--The reference here, of course, is to His manifestation to the two disciples going to Emmaus, so exquisitely told by the Third Evangelist (see on Luke 24:13, &c.).

Jesus next appeared to Peter (Luke 24:34; 1-Corinthians 15:5).
After that. On the afternoon of the same day (Sunday) (Luke 24:13-32).
He appeared in another form. Luke explains this by saying that their eyes were holden. If their eyes were influenced, of course, optically speaking, Jesus would appear in another form.

Luke 24:13.