Acts 1:24

Though the imperial power be great, yet consider, O Emperor, how great God is. He sees the hearts of all, He questions the inmost conscience, He knows all things before they happen, He knows the inmost things of your breast. You do not suffer yourselves to be deceived, and do you desire to conceal anything from God?

"They appointed two," it is said, "Joseph called Barsabus, who was surnamed Justus, and Matthias. And they prayed, and said; Thou, Lord, which knowest the hearts of all men, show whether of these two thou hast chosen, that he may take part of this ministry and Apostleship, from which Judas by transgression fell, that he might go to his own place." They do well to mention the sin of Judas, thereby showing that it is a witness they ask to have; not increasing the number, but not suffering it to be diminished.

And they all pray in common saying, "Thou, Lord, which knowest the hearts of all men, show. Thou," not "We." And very seasonably they use the epithet, "heart-knowing:" for by Him Who is this must the choice be made. So confident were they, that assuredly one of them must be appointed. They said not, Choose, but, "Show the chosen one;" knowing that all things were foreordained of God; "Whom Thou didst choose: one of these two," say they, "to have his lot in this ministry and apostleship." For there was besides another ministry.

A lottery takes place to avoid contention and to assure greater certitude and clarity. The source of this rule is the counsel of God. The apostles imply the idea when they say, Lord, who knowest the hearts Thus it is clear that the lot does not happen by chance but by the power of God.

They call him a discerner of hearts at the right time; and they do not say, "Choose," but, "Appoint the one chosen." For all things are known and the best are with God, and before our considerations. And he calls it an inheritance, showing the whole of God's love and choice, and recalling the ancients, that he likewise allotted the Levites in this way.

They cry out in prayer to the Knower of Hearts at the fitting time. They do not go on to say "choose," but "show… the one whom You have chosen," knowing that with God all things are determined before human thought.