Translation
I am the counter, and I do the counter to the scholar before me. He wants to make a dagger play, that is, the second play after the first remedy master. If you remain on your feet with your sword, I will not believe it.
Interpretation
From the play of the 3rd master, your opponent has cut their left hand up between your right forearm and the sword handle, as shown by the 13th scholar. They are attempting to put you into a middle bind. Fiore says this is a dagger play, which it is, but the best example of this bind using swords is the 4th scholar of sword in one hand.
Lunge forward and to the side with your right foot to the outside of your opponent. Place your right hand and the sword against the back of your opponents shoulder. As you do this, pivot 180 degrees on the balls of your feet and pull your left foot towards you a little. Make sure that your hips are pushed up next to your opponent. Lean your weight forward onto your left foot. Their left hand will be twisted behind their back in a lower bind.
Grab your sword with your left hand. Push against the back of your opponents left shoulder with your right hand. Use your left hand to add power and leverage, bending your opponent over and tightly binding their arm, as the picture shows.
Keep pushing down with your left hand to ensure your opponent remains head down and immobile. You can easily control the level of pain inflicted by raising or lowering your right elbow.
Fiore often uses the lower bind. You can see other examples and variants of this lock in the following plays.