John Calvin Commentary Acts 21:5

"And when it came to pass that we had accomplished the days, we departed and went on our journey; and they all, with wives and children, brought us on our way till we were out of the city: and kneeling down on the beach, we prayed, and bade each other farewell;" — Acts 21:5 (ASV)

With their wives and children. This was no small testimony of love, in that they accompanied Paul out of the city with their wives and children. Luke reports this, partly so that he might commend their godliness as it deserved, and partly so that he might declare that Paul received the honor that was due to him.

From this we also gather that he was fully intent on providing for his own advantage, since he was not held back by such great goodwill, which was a pleasant enticement for him to stay.

And we must also note the solemn custom of praying in more important matters, and that when they were informed by God of the danger, they were even more stirred up to pray.