Acts 4:31

"And when they had prayed, the place was shaken where they were assembled together." This was the proof that they were heard, and of His visitation. "And they were all filled with the Holy Ghost." What means, "They were filled?" It means, They were inflamed; and the Gift burned up within them. "And they spake the word of God with boldness."

"For when they had prayed," it is said, "the place was shaken." And wherefore this was done, hear from the prophet, when he says, "He looketh on the earth, and maketh it to tremble." For by this He made it manifest that He is present to their prayers. And again, another prophet saith, "The earth was shaken, and did tremble at the presence of the Lord." And God did this, both to make it more awful, and to lead them on to a courageous trust. "And they were all filled with the Holy Ghost, and they spake the word of God with boldness." They gained increased boldness. As it was the beginning of their work, and they had besought a sensible sign for their persuasion-but after this we nowhere find the like happening-therefore great was the encouragement they received. In fact, they had no means of proving that He was risen, save by miraculous signs. So that it was not only their own assurance that they sought: but that they might not be put to shame, but that they might speak with boldness.

"The place was shaken," and that made them all the more unshaken. For this is sometimes a token of wrath, sometimes of favor and providence, but on the present occasion, of wrath. For in those times it took place in an unusual manner. Thus, at the Crucifixion, the earth was shaken: and the Lord Himself says, "Then there shall be famines, and pestilences, and earthquakes in divers places." But then the wrath of which it was a sign was against the adversaries: as for the disciples, it filled them with the Spirit. Observe, even the Apostles, after the prayer, are "filled with the Holy Ghost."