SCRIPTURE COMMENTARY #628
Saying: "The Lord is risen indeed and hath appeared to Simon." And they told what things were done in the way: and how they knew him in the breaking of bread.
THE APPARITION TO PETER: Our Lord appeared to St. Peter before any of the other apostles 1. to distinguish him as the chosen head of His Church; 2. to repay him for the greater love he bore Jesus than the others; 3. to assure him of His forgiveness, and to show to the whole world how pleasing to Him were Peter's tears of contrition, and how willing He is to forgive repentant sinners.
[From 'A Practical Commentary on Holy Scripture' by Bishop Knecht, D.D.]
(1899 Douay-Rheims Bible)