Комментарий к Шмот 4:8

והאמינו לקל האת האחרון THEY WILL BELIEVE THE VOICE OF THE LATTER SIGN — As soon as you say to them, “On your account have I been smitten — because I uttered slander about you”, they will believe you, for they are already experienced in this: that those who combine to harm them are smitten by plagues, e. g., Pharaoh and Abimelech who were punished on Sarah’s account.

והאמינו לקול האות האחרון, from a medical science point of view the ability to heal tzoraat was a far greater miracle as it meant bringing back to life a limb which had already died ולקחת ממימי היאור, seeing that water is a basic liquid, one of the four basic raw materials earth is constructed of, converting this into blood without adding any additional ingredient to it was a most remarkable miracle.

והיה אם לא יאמינו, “in the event that they will not believe you, etc.” Ibn Ezra writes that seeing that we know full well whether or not the Israelites would believe Moses’ claim to be the redeemer appointed by G’d, it is clear that this verse was addressed only to Moses, to tell him that in the event that some of the people would not believe that Moses was the chosen redeemer after having seen the first miracle, the second miracle would convince also these doubters. As to the Torah describing the reaction of the people to the miracle as a קול האות, a miracle with an audible impact, rather than as it having a visual impact, this is an example of what Rabbi Yishmael had described as the Torah employing a syntax familiar to the common people. Furthermore, as to the Torah describing the second miracle as אות האחרון, “the last miracle,” when in fact it would be followed by a third miracle, the reason is that as of that point in time only two miracles had been demonstrated to Moses. The verse hints that if after two miracles there would still be doubters, a third miracle would be performed which would silence the remaining doubters. As a matter of fact, in due course, Moses performed these miracles, and the people all believed that he was the chosen redeemer. (verses 30-31)

והאמינו לקול האות האחרון, “they will believe and pay heed to the second miracle.” G’d referred to the miracle involving the tzoraat as the “last” one instead of as “the second one,” as it was the last one relative to the first one. Besides, it was the last miracle Moses performed in the desert where he had no audience.

Once you tell them, “because of you I was struck [with tzora’as]” . . . they will believe you. [Rashi offers this explanation because] otherwise the last sign is no better than the first. [Rashi offers this explanation because] otherwise the last sign is no better than the first. The Re”m asks: “But [according to this,] I do not know what Rashi would say regarding the sign of [water turning to] blood. How is it better than the two preceding signs?” It would seem the answer is: the B’nei Yisrael did not actually see the first two signs, thus they might not believe them. But the sign of blood they will see with their own eyes, therefore they will believe in it. And Moshe was not commanded to perform the first two signs [before them] because these signs served also to punish Moshe, as Rashi explained, [and it would not be proper to punish Moshe in front of them]. The Maharshal explains [why the first two signs were not repeated]: For if we say the tzora’as punished Moshe for slander, then he had received his [due amount of] suffering from Hashem the first time, and need not be afflicted with tzora’as again. And if we say it was not because of Moshe’s sin, then surely Hashem would not make him suffer a second time for naught.

והאמינו לקול האות האחרון, “they will believe in the effect of the (sound) of the last miracle.” Healing the skin disease of tzoraat was so unheard of that it would convince the people that Moses had been sent by G-d as only He could do this.