The other apostles being chosen by God immediately, it was necessary that he who was to act in the same office, should be chosen after the same manner. Knowest the heart, which is God's prerogative only; all others may be, and often are, mistaken by outward appearances.
Related Commentaries of Acts 1:24
Acts 1:24
24 And they prayed, and said, Thou, Lord, which knowest the hearts of all men, shew whether of these two thou hast chosen,