1 Corinthians 15:5-9 and that he was seen of Cephas, then of the twelve:

Haweis⁽ⁱ⁾ ⁵ and that he was seen of Cephas, then of the twelve: ⁶ afterwards he appeared before five hundred brethren at once; of whom the greater number remain alive unto this hour, but some also are gone to rest. ⁷ Afterwards he was seen of James; then of all the apostles. ⁸ And last of all he was seen also by me, who am but as an abortion. ⁹ For I am the least of the apostles, who am not meet to be called an apostle, because I persecuted the church of God.