This chapter is really more or less a buildup of the “great plague”. God tells Moses that after this plague he will let you go. Moses is instructed to go and tell Pharaoh what is about to come; that God will strike down the first born of every Egyptian child. But it doesn’t end there. It doesn’t even begin there. We hear before that God instructing all to ask for gold and silver for their neighbor because they are about to get out of this country. I guess this is a type of covert plundering of the nation.
The sign that this act is happening and that it is of the Lord is that dogs will cease growling at the Israelites. They will growl at every other person group, but they will no longer growl at the Israelites. That is a bit curious. We have a dog who doesn’t growl, but loves to bark. We don’t love it when she barks. But if she were to bark just at certain types of people or just certain ethnicities, that would be very curious indeed. But for the plague of the Passover, which we will see next chapter, the whole growling of dogs is part of it.
Moses tells Pharaoh of what is about to come and he leaves Pharaoh in ‘hot anger’ because he knows, he just knows that he will not listen to him. In fact, God confirms that fact in the next paragraph. The plague, the terrible plague comes next.