Acts 1:24

And they prayed, and said, Thou, Lord, who knowest the hearts of all men, show of these two the one whom thou hast chosen.

Lord ... This could refer either to the Father or to the Lord Jesus. As Bruce said:

As the verb used in "thou hast chosen" (end of Acts 1:24) is the same as that used in "he had chosen" (end of Acts 1:2), it is reasonable to conclude that Jesus is the subject here as in the former place.[26]