Or HaChaim on Exodus 6:1/אור החיים על שמות ו׳:א׳

1 עתה תראה אשר אעשה לפרעה, "Now you are about to see what I shall do to Pharaoh, etc." The word עתה was G'd's answer to Moses' ומאז באתי, that G'd had made things worse for Israel than prior to Moses' appointment. G'd told Moses that not only would the additional hardships cease forthwith but also the hardships endured by the people up until then would come to an end immediately. We have already mentioned that slave labour ceased from the time the river Nile was struck and turned into blood. G'd made it plain to Moses that not only had he been wrong in assuming that the most recent decree of Pharaoh would last for twelve months, but even his previous decrees would become inoperative at once.

2G'd also answered Moses concerning what Moses had perceived as G'd's failure to respond to the way Pharaoh had slighted Him. This is why He told Moses that He would smite him until Pharaoh would dismiss the Israelites because he had experienced G'd's strong hand. We explained already that G'd delayed the final plague in order to punish Pharaoh for his blasphemy.

3וביד חזקה, "and with a mighty hand, etc." This second reference to G'd's mighty hand was a preview of the consternation G'd would cause at the time of the killing of the firstborn when the Torah reports that there was not a single house in Egypt in which not at least one person died at that time (compare Yalkut Shimoni on Exodus 12,30 where it is explained that if there was no actual firstborn in a specific house at the time, the oldest would be killed). As a result of all this the Egyptians would not only dismiss the Israelites but would actually יגרשם, "expel them," as each Egyptian feared for his own life every minute (compare Exodus 12,33). G'd answered Moses' other argument as to why He had allowed things to get worse in the next פרשה.