John Wesley on Acts 8:21

Thou hast neither part - By purchase, nor lot - Given gratis, in this matter - This gift of God. For thy heart is not right before God - Probably St. Peter discerned this long before he had declared it; although it does not appear that God gave to any of the apostles a universal power of discerning the hearts of all they conversed with; any more than a universal power of healing all the sick they came near. This we are sure St. Paul had not; though he was not inferior to the chief of the apostles. Otherwise he would not have suffered the illness of Epaphroditus to have brought him so near to death, Php 2:25 - 27; nor have left so useful a fellow labourer as Trophimus sick at Miletus, 2Tim 4:20.