Adam Clarke on Joshua 6:25

And she dwelleth in Israel even unto this day - This is one proof that the book was written in the time to which it is commonly referred; and certainly might have been done by the hand of Joshua himself, though doubtless many marginal notes may have since crept into the text, which, to superficial observers, give it the appearance of having been written after the days of Joshua. See the preface to this book.