10:6 Simon a tanner, whose house is by the sea side. See PNT Ac 9:43. Tanners were required, by the ancient sanitary laws, to live outside city walls, and had to be near plenty of water (Hackett).
Tell thee what thou oughtest to do. As the angel says that his prayer was heard, he had surely prayed that he might know what to do.
10:1-8 Hitherto none had been baptized into the Christian church but Jews, Samaritans, and those converts who had been circumcised and observed the ceremonial law; but now the Gentiles were to be called to partake all the privileges of God's people, without first becoming Jews. Pure and undefiled religion is sometimes found where we least expect it. Wherever the fear of God rules in the heart, it will appear both in works of charity and of piety, neither will excuse from the other. Doubtless Cornelius had true faith in God's word, as far as he understood it, though not as yet clear faith in Christ. This was the work of the Spirit of God, through the mediation of Jesus, even before Cornelius knew him, as is the case with us all when we, who before were dead in sin, are made alive. Through Christ also his prayers and alms were accepted, which otherwise would have been rejected. Without dispute or delay Cornelius was obedient to the heavenly vision. In the affairs of our souls, let us not lose time.
