Rashi on Deuteronomy 20:14/רש"י על דברים כ׳:י״ד

1והטף AND THE LITTLE ONES [… SHALT THOU TAKE UNTO THYSELF] — the male children, too. But how am I to understand (v. 13) “and thou shalt smite every male thereof”? As referring to the male adults (Sifrei Devarim 200:7).