Commento su Deuteronomio 23:14

על אזנך [AND THOU SHALT HAVE A PIN] על אזנך — i.e. besides (על, “in addition to”, not “upon”) your other implements.

על אזניך, in addition to your other equipment.

ויתד תהיה לך על אזנך, “you are to have a shovel in addition to your gear (weapons).” The letter א at the beginning of the word אזנך is an addition, not part of the root. The basic word is זין, weaponry. The shovel is supposed to be an integral part of your equipment in war, no less important than your weapons. This commandment reflects he spiritually high level of a Jewish camp. It reflects the awareness by the Jewish soldiers that the Shechinah is in their midst. At the same time, the need for the shovel indicates that the Torah speaks of a period when the people had already become guilty of sins seeing that during the years when they did not sin there was no need for a shovel as the manna was completely absorbed by their bodies so that there was no excrement which had to be covered up. Not only that, but it also absorbed the taste of other foods. After the Israelites had begun to sin, they did need shovels to clean up after themselves. I have already discussed this matter in Numbers 11,5.
Our sages in Yuma 75 explain that when the Israelites defecated they did not do so sideways or forwards but behind themselves so as not to expose their excrement to the clouds of glory which accompanied the Israelites on both their flanks and in front of them.

Aside from your other utensils. I.e., you are to have a peg aside from your other utensils in order to dig with it.

ויתד תהיה לך על אזנך, ”you shall have a paddle amongst your weapons;” seeing that with a few exceptions most of the people going out to fight a war are males, and seeing that they had the Holy Ark with them and they were not able to build separating walls, which would have insulated it from exposure to contaminated air by the ritually impure, the people who had nocturnal seminal emissions and should by rights have left the camp, could not do so because of the danger. This is why every one had to dig his own hole to bury his excrement and cover it.

אזנך has the same meaning as זין in the phrase כלי זין.