18 Then the Spirit came upon Amasai, the leader of the Thirty, and he said, "We are yours, David! We are on your side, son of Jesse. Peace and prosperity be with you, and success to all who help you, for your God is the one who helps you." So David let them join him, and he made them officers over his troops.
Matthew Henry's Commentary on 1 Chronicles 12:18
Commentary on 1 Chronicles 12:1-22
(Read 1 Chronicles 12:1-22)
Here is an account of those who appeared and acted as David's friends, while he was persecuted. No difficulties or dangers should keep the sinner from coming to the Savior, nor drive the believer from the path of duty. Those who break through, and overcome in these attempts, will find abundant recompence. From the words of Amasai we may learn how to testify our affection and allegiance to the Lord Jesus; his we must be throughly; on his side we must be forward to appear and act. If we are under the influence of the Spirit, we shall desire to have our lot among them, and to declare ourselves on their side; if in faith and love we embrace the cause of Christ, he will receive, employ, and advance us.