Luke
Acts 2:19ESV·traditional attribution

And I will show wonders in the heavens above and signs on the earth below, blood, and fire, and vapor of smoke;

John Calvin Reformed @genevareformer

19. And I will show wonders We must first see what is meant by this great day of the Lord. Some do expound it of the former coming of Christ in the flesh; and others refer it unto the last day of the resurrection, I do allow neither opinion. For, in my judgment, the prophet comprehendeth the whole kingdom of Christ.

Matthew Henry Presbyterian @wholebiblehenry

We have here the first-fruits of the Spirit in the sermon which Peter preached immediately, directed, not to those of other nations in a strange language (we are not told what answer he gave to those that were amazed, and said, What meaneth this?) but to the Jews in the vulgar language, even to those that mocked; for he begins with the notice of that...

Commenting on Acts 2:14-36

John Gill Reformed Baptist @doctorgill

And I will show wonders in heaven above,.... The word above is not in Joel, nor in the Syriac version here, as neither the word "beneath", in the next clause. This may refer either to the appearance of angels, and of an extraordinary star at the birth of Christ; or rather to comets and blazing stars, and particularly to that comet which, in the form...