Acts 16:32

And they spake unto him the word of the Lord - Thus, by teaching him and all that were in his house the doctrine of the Lord, they plainly pointed out to them the way of salvation. And it appears that he and his whole family, who were capable of receiving instructions, embraced this doctrine, and showed the sincerity of their faith by immediately receiving baptism. And, by the way, if he and all his were baptized straightway, παραχρημα, immediately, instantly, at that very time, dum ipsa res agitur, it is by no means likely that there was any immersion in the case; indeed, all the circumstances of the case, the dead of the night, the general agitation, the necessity of despatch, and the words of the text, all disprove it. The apostles, therefore, had another method of administering baptism besides immersion, which, if practised according to the Jewish formalities, must have required considerable time, and not a little publicity. As the Jews were accustomed to receive whole families of heathens, young and old, as proselytes, by baptism, so here the apostles received whole families, those of Lydia and the jailor, by the same rite. It is therefore pretty evident that we have in this chapter very presumptive proofs:

1. That baptism was administered without immersion, as in the case of the jailor and his family; and

2. That children were also received into the Church in this way; for we can scarcely suppose that the whole families of Lydia and the jailor had no children in them; and, if they had, it is not likely that they should be omitted; for the Jewish practice was invariably to receive the heathen children with their proselyted parents.

To all that were in his house - Old and young. They instructed them in the doctrines of religion, and doubtless in the nature of the ordinances of the gospel, and then baptized the entire family.