Or HaChaim on Exodus 7:4/אור החיים על שמות ז׳:ד׳

1 ולא ישמע אליכם פרעה, "and Pharaoh will not listen to you." Why did the Torah have to say that Pharaoh would not listen to Moses and Aaron after G'd had already said in verse three that He would harden the heart of Pharaoh? We also need to understand what G'd meant when He spoke about placing His hand on Egypt, which appears to mean something over and beyond the plagues with which G'd will strike Pharaoh and the Egyptians.

2I believe that we must understand the verse thus: First of all, G'd announces that He would harden Pharaoh's heart as a result of which He would bring many plagues upon him. The plagues would prove counterproductive (initally) and make Pharaoh even more obstinate, adding still more sins to his already considerable culpability. Eventually, he would not even want to listen to what Moses and Aaron had been instructed to tell him. This is in fact what happened in 10,28 when Pharaoh bans Moses and Aaron from appearing again in His presence. G'd announces to Moses already at this point that when that stage will be reached it would be the limit of obstinacy that Pharaoh is allowed. Immediately after that ban G'd brought the final plague of the dying of the Egyptian firstborns upon him, as a result of which he would not only release the Israelites but expel them.

3We find confirmation of this meaning of the word "My hand," when we read in Chronicles I 21,16 that David observed the angel of death with drawn sword in "his hand." In our instance, G'd refers to the fact that He personally would bring this plague upon Pharaoh by describing His activity as ידי, "My hand." This is why the Mechilta on Exodus 11,4 states that He Himself would be active as distinct from any of His agents. G'd also alluded to the destruction He would bring upon the various Egyptian deities at that time.

4When we keep all this in mind we can understand Moses' comment that "I will not continue to see your face," which appears as somewhat high-handed at first. Whence did Moses know that G'd would not send him to speak to Pharaoh again in spite of Pharaoh's threat? The answer is that Moses had been told already in our verse exactly how things would develop. Instead of questioning Moses' statement we should congratulate him on recognising that Pharaoh had reached the end of his rope when he forbade Moses and Aaron to appear before him and threatened to have them executed in the event they would come to him again. Up until then Pharaoh had only refused to listen to G'd's instructions. The moment he even refused to grant an interview to G'd's messengers he had forfeited all further consideration. Actually, this was already the second allusion to the eventual slaying of the firstborn, the first time being when G'd referred to "My firstborn, Israel," as I have demonstrated in my commentary on 4,22.

5והוצאתי את צבאותי את עמי, "I will take out My hosts, My people, etc." Who exactly are the ones G'd describes as צבאותי, "My hosts?" If the reference is to the Israelites, the Torah should have written: את צבאות עמי, "the hosts who are My people." Perhaps G'd wanted to illustrate the superior stature of the Israelites, i.e. that of all of G'd's hosts none could compare to His people Israel. Had the Torah used the words: את צבאות עמי, the impression would have been created that G'd has many hosts, the Israelites being merely one of many. By saying צבאותי, further identification became unnecessary as only one people qualified for such a description. Subsequently the Torah does identify G'd's people by mentioning Israel by name. The whole verse can be understood according to the classic principle of כלל ופרט. Whenever that rule is applied the פרט, i.e. the details are automatically closely related to what is stated in the כלל, the subject in the general statement, i.e. only the Israelites could have been meant in the description צבאותי. The Torah therefore wanted the world to know that as of that moment whenever mention is made of G'd's hosts only the Israelites are meant.