1 Corinthians 15:5

And that he appeared to Cephas; then to the Twelve.

Cephas ... is the name for Peter; and one significant thing is that the Lord made a special appearance to the apostle who had denied him, giving hope to all who fall, and showing that the Lord is tender and merciful to forgive our sins (see Luke 24:34). Some have criticized Paul for omitting the appearances to the women (John 20:14); but those do not belong here, since they were "evidential to the apostles, rather than to the world,"[10] and came at a time when the apostles themselves were in a state of shock and unbelief.

Then to the Twelve ... This is a reference to the office of the Twelve, and the fact of Jesus' appearances being to ten on one occasion and eleven on another is a mere quibble of no importance at all.