Charles Spurgeon Commentary Acts 2:36-37

"Let all the house of Israel therefore know assuredly, that God hath made him both Lord and Christ, this Jesus whom ye crucified. Now when they heard [this,] they were pricked in their heart, and said unto Peter and the rest of the apostles, Brethren, what shall we do?" — Acts 2:36-37 (ASV)

Therefore let all the house of Israel know assuredly, that God has made that same Jesus, whom you have crucified, both Lord and Christ. Now when they heard this, they were pricked in their heart,

A little later in this same Book, we read of those who listened to Stephen's sharp, sword-like sentences, When they heard these things, they were cut to the heart, and soon they stoned Stephen to death. To be "cut to the heart" is not enough, but to be pricked in the heart is to receive a mortal wound.

Happy is the man who has had his sin killed through having received a deadly wound from the sword of the Spirit, which is the Word of God. These people who heard Peter preach were pricked in their heart, and, first, they were in doubt as to what they should do but, secondly, they were resolved that, whatever they should be told to do, they would do at once.