John 20:2-5, The Race to the Tomb
So [Mary Magdelene] came running to Simon Peter and the other disciple, the one Jesus loved, and said, “They have taken the Lord out of the tomb, and we don’t know where they have put him!” So Peter and the other disciple started for the tomb. Both were running, but the other disciple outran Peter and reached the tomb first. He bent over and looked in at the strips of linen lying there but did not go in.
//All through John’s Gospel, the “disciple Jesus loved” and Peter seem to be in a bit of a contest. Here, the two of them race to the tomb, and the Beloved Disciple wins the race. But when he gets there ahead of Peter, he refuses to enter the tomb.
Why? Is he just being a scaredy-cat? Does he defer to Peter, the elder?
If the Beloved Disciple is really John the Apostle, as tradition suggests, then there is a more likely answer. Recall that John’s father, Zebedee, was a priest. That puts John in line for priesthood, too. And that means he should respect the rules of the priesthood.
Therefore, when he gets to the tomb, he can’t enter until he knows there is no corpse inside. To do so would make him ritually unclean. But as soon as Peter enters, and verifies that it’s safe, John goes in too.