בא אל פרעה...מביא מחר. ומשה היאך ידע והלא לא מצינו שאמר לו הקב"ה מכת הארבה י"ל שהיו חקוקות על המטה דצ"ך עד"ש באח"ב וק"ל א"כ במכות אחרונות אמאי הוצרך להודיעו לכן נ"ל דהבין משה המכה מדאמר לו הקב"ה למשה ולמען תספר ודרך הוא לספר על מכת הארבה שהרי גם במכת הארבה דיואל כתיב עליה לבניכם ספרו: בוא אל פרעה....מביא מחר, “go in unto Pharaoh...I will bring on the plague of locusts tomorrow to your territories.” How had Moses had advance warning of this plague, seeing that we have no word in the Torah where G–d had given him advance notice about this plague? We will have to fall back on the tradition that the acronyms of the ten plagues as per Rabbi Yehudah, had been etched into the side of his staff. The problem with this interpretation is that if so why did G–d bother to give him advance notice of the two plagues following after the plague of locusts? It may be more plausible to assume that the words למען תספר באזני בנך ובן בנך את אשר התעללתי במצרים, “in order that you will be able to tell your son and your grandson what I have wrought upon Egypt,” (verse 2) that this had included details about the forthcoming plague of locusts. We find that the plague of locusts recorded in the Book of Yoel (Yoel 1,3-4) was also introduced by the prophet telling his people to tell his children and grandchildren about it. [In that instance the plague of locusts smote the land of Israel. Ed.]