Commentary
Here the priest's special longpoint is besieging quarta custodia. This possibly happened because the scholar was using priest's special longpoint to close in the grappling distance, and the priest saved himself by stepping back to keep the distance, and retreating into quarta custodia.
This is a situation with unclear initiative, as both positions are aggressive and ready to deliver a strike. If the scholar is faster, he will do schutzen to preemptively cover the strike from above and will follow the retreating priest. If he gets close enough, he will hit with a thrust. This is explained at the first paragraph.
If the priest is faster, he will strike the scholar who is going into schutzen, which will result in a bind. From here the priest rebinds and forces the scholar into binding below and on the left, to which the scholar reacts by pull and push, thrusting above. This is shown in third and fourth images. The scholar's reaction involves leaving the bind, and thus the text mentions the play of binder and the bound.
The last image is showing the priest defending the scholar's last action. According to the play of binder and the bound, the priest follows scholar's action and hits first. This last image is wierd, because the scholar is drawn with the sword above his head, pointing back. This is a position in which he can't get, because he was going for a thrust, while the position portrayed is reasonable only for cutting. It is possible, that the last image is showing a different action, which was also possible to be done in reaction to the priest'a rebind - a durchtretten. As the play of the binder and the bound is very general, it will apply in both cases.