鈴木よ、聞いてやるな。そちらの道には君の息子が気に入っている娘がいるのだ
Context: 鈴木 asks his son what was in that direction since his son was looking that direction. Then someone else said the above sentence.
I'm confused about the part 鈴木よ、聞いてやるな. It's especially confusing how the 'な ' is used here. Can anyone can help me?