1 Corinthians 9:2

1 CORINTHIANS—NOTE ON 1 Corinthians 9:2 seal. Seals in the ancient Near East were used to guarantee the quality and authenticity of a document (such as a letter) or product (such as wine); see note on John 6:27. Paul’s gospel preaching has changed the hearts of the Corinthians. That change shows that his apostleship is genuine. See also 2 Corinthians 1:21; 2 Corinthians 3:3.