Charles Ellicott Commentary Acts 11:23

"who, when he was come, and had seen the grace of God, was glad; and he exhorted them all, that with purpose of heart they would cleave unto the Lord:" — Acts 11:23 (ASV)

And exhorted them all.—The tense implies continuous action; and the verb in the Greek is that from which Barnabas took his name as the “Son of Comfort” or “Counsel.” (See Note on Acts 4:36.)

With purpose of heart.—The preacher had seen the grace of God, and had rejoiced at it; but he knew, as all true teachers know, that it is possible for man’s will to frustrate that grace, and that its cooperation, as manifested in deliberate and firm resolve, was necessary to carry on the good work to its completion. The word for “purpose” meets us again in Acts 27:13.

They would cleave unto the Lord.—The noun is probably used in its dominant New Testament sense, as pointing to the Lord Jesus as the new object of the faith and love of those who had turned to Him.