Acts 5:19

“But the angel of the Lord, etc.] Or “of God”, as the Arabic and Ethiopic versions read, whether Michael, as some have thought, or Gabriel, or what particular angel, is not material to know. However, it was a good angel, an elect angel, one of those ministering spirits sent by God to minister to the heirs of promise; one of those angels that excel in strength, as appears by what he did: for he by night opened the prison doors; where the apostles were put, and which had more doors than one, and these strong and close shut, and guarded by keepers; but were easily opened by the angel. It was very likely at, or towards the evening, when the apostles were taken, and therefore they were committed…”

“by night--the same night.”

“But the angel of the Lord - This does not denote any “particular” angel, but simply an angel. The “article” is not used in the original. The word “angel” denotes properly a “messenger,” and particularly it is applied to the pure spirits that are sent to this world on errands of mercy. See the notes on Matthew 1:20. The case here was evidently “a miracle.” An angel was employed for this special purpose, and the design might have been: To reprove the Jewish rulers, and to convince them of their guilt in resisting the gospel of God; To convince the apostles more firmly of the protection and approbation of God; To encourage them more and more in their work, and in the faithful discharge of their…”

“5:19-20 The irony here is that the Sadducees denied the existence of angels (23:8). Angels frequently intervened in Acts (see also 10:3, 7, 22; 11:13; 12:6-11, 23; 27:23-24). Luke presents God as guiding his people in their ministry, using angels to accomplish his purpose.”

“Act 12:7-11, Act 16:26; Psa 34:7, Psa 105:17-20, Psa 146:7; Isa 61:1 Acts 5:20”