Magic is like an ethereal tooth and of little value

A question it has arisen. Very early in the novel Vir remembers this saying, “Magic is like an ethereal tooth and of little value.” Nevertheless, magic serves an importance in the novel that belies the saying. Why is this true? There are two reasons. First is Vir had very little magic ability in the world he came from, so what is about to happen is a surprise to him. The second reason occurs in a later novel in the series. Look for this phrase to reappear.