Translation
With the arms crossed I wait for you without fear. Whether you attack from below or above I do not care, because any way you attack me you will be bound. Either in the middle bind or in the lower you will be locked. Although if I wanted to make the grips of the fourth remedy master of dagger, with those plays I would badly hurt you. And I would not fail to take your dagger.
Interpretation
Your opponent grabs you to hold you still while they deliver a dagger attack. Ignore the hand which has made the grab and step forward into posta tutta porta di ferro incrosada e dopia. What happens next is not a specific play, but rather any of a number of possible actions depending on the circumstances of the moment and your own personal preferences.
As the attack is delivered, push your crossed forearms under the dagger and against your opponents right wrist. This jams the attack and makes the cover of the 2nd master of dagger. From here, you can continue as the 2nd master or any of their scholars.
If you release your right hand, you will effectively find yourself making the cover of the 1st master of dagger. From there you can move to any of the 1st master plays, although Fiore specifically recommends the middle bind as the 1st scholar demonstrates.
Similarly, you can drop your left hand away, which leaves you in the cover of the 3rd master of dagger. This gives you the opportunity to transition to any of the 3rd master plays. Most of these are variations on the lower bind, best demonstrated by the 5th scholar of the 3rd master.
By using a ‘sticky hands’ approach, and maintaing contact with your opponents arms, you can also transition to any of the plays of the 4th master of dagger.
There is a lot of unrealised potential in this play. More than anything, it is a lesson in free flowing movement and adaptability, not only in your physical actions but your thought processes as well.