Sforno on Numbers 14:13/ספורנו על במדבר י״ד:י״ג

1ושמעו מצרים, Moses thought that when G’d had said: “I will smite them with pestilence” that He had in mind to strike all of them immediately, simultaneously. He therefore felt impelled to question what would this do to G’d’s great name? Surely, he argued, the Egyptians would ascribe this to G’d’s impotence in making good on His promise to this people, 'מבלתי יכולת ה' להביא את העם וגו, they would claim that G’d’s power did not include dealing with the Canaanites. Seeing that the Egyptians are aware of the effort You expended in liberating them from slavery in Egypt, and they are further aware that You have made the seat of Your residence on earth in their Tabernacle, the mere thought that You would now kill them on account of a sin would never occur to them