2 John 1:4 - Joseph Benson’s Commentary on the Old and New Testaments

I rejoiced greatly that I found of thy children That is, some of thy children; walking in truth In a manner agreeable to the gospel. It is probable that John speaks of such of her children as he had met with in the course of his travels, probably at their aunt's house, 2 John 1:13; and that having conversed with them, and observed their conduct, he had found reason to conclude that they were truly pious, and sound in the faith. After their return home, it seems, he inscribed this letter to them as well as to their mother, and by the commendation which he bestowed on them in it, he no doubt encouraged them much to persevere in the truth. By the joy which this circumstance gave the apostle, was manifested the disposition of a faithful minister of Christ; for such derive great happiness from the faith and holiness of their disciples.