Much disputing - Or rather, much inquiry or deliberation. With our word disputing we commonly connect the idea of heat and anger. This is not necessarily implied in the word used here. It might have been calm, solemn, deliberate inquiry; and there is no evidence that it was conducted with undue warmth or anger.
Peter rose up and said - Peter was probably the most aged, and was most accustomed to speak, Acts 2:14, etc.; Acts 3:6, Acts 3:12. Besides, there was a particular reason for his speaking here, as he had been engaged in similar scenes, and understood the case, and had had evidence that God had converted sinners without the Mosaic rites, and knew that it would have been inexpedient to have imposed these rites on those who had thus been converted.
A good while ago - See Acts 10: Some time since. So long since that there had been opportunity to ascertain whether it was necessary to observe the laws of Moses in order to the edification of the church.
God made choice ... - That is, of all the apostles, he designated me to engage in this work. Compare the notes on Matthew 16:18, with Acts 10.
That the Gentiles - Cornelius, and those who were assembled with him at Caesarea. This was the first case that had occurred, and therefore it was important to appeal to it.