John Gill Commentary Matthew 28:16

"But the eleven disciples went into Galilee, unto the mountain where Jesus had appointed them." — Matthew 28:16 (ASV)

Then the eleven disciples went away into Galilee. For Judas was not only gone from them, but was dead, so that there were now but eleven of them. They did not go directly, as soon as the women had delivered their message, for Christ appeared to them the same day at Jerusalem, and so he did at the same place that week (see John 20:19, John 20:26). But some time after this, they went together into Galilee, according to Christ's direction both before and after his resurrection (Matthew 26:32, 28:10).

They went into a mountain where Jesus had appointed them, either before his death, or since he was risen, and very likely at one of the above interviews he had with them. This is generally thought to be Mount Tabor, but of this there is no proof, nor certainty. It might be the mountain near Capernaum, on which he taught (Matthew 5:1), or that, if not the same with the other, near the sea of Galilee, where Christ fed four thousand with seven loaves, and a few fishes (Matthew 15:29). A mountain was appointed for this meeting, both for solitariness and for sight, for here it was he was seen by above five hundred brethren at once (1 Corinthians 15:6).