Adam Clarke on John 21:1

Jesus showed himself again - After that our Lord had appeared several times to the women, and to the apostles at Jerusalem, and at the tomb, he bade them go into Galilee, giving them the promise of meeting them there: Mat 28:7; Mar 16:7. This promise we find he fulfilled in the way John relates here. This was the seventh appearance of our Lord after the resurrection. Matthew, Mat 28:16, has but just mentioned it: of it the rest of the evangelists say nothing, and this is the reason why John gives it so particularly.