Shlach - Power of the Tzaddik

And the L-rd said, "I have forgiven them in accordance with your word.

  וַיֹּאמֶר  ה' סָלַחְתִּי כִּדְבָרֶךָ 

Bamidar 14:20

Rashi says for in accordance with your word: Because of what you said, namely,“They might say that Hashem lacks the ability..."

Kedushat Levi is quite surprised by Rashi's statement, explaining the meaning of Rashi as where Moshe prayed to Hakadosh Baruch Hu in support of Yisrael with the claim that there shouldn't be (ח"ו) a chillul hashem (desecration of the name) as mentioned in the verse But the Egyptians will hear: meaning "They will hear that You killed them."

This is difficult! Does it not lie with the Hakadosh Baruch Hu the thoughts of all mankind, and aren't all the ways of man bent towards the will of Hashem? Then shouldn't Hashem simply be able to bend the thoughts of the nations to not say anything critical of Hashem and not have a chillul hashem?

However the power of a Tzaddik's speech makes a great impression both above and below, as it says in Iyov "You will make a decision, and it will be accomplished for you, and light will shine on all your ways."(Iyov 22:28) -  וְתִגְזַר אוֹמֶר וְיָקָם לָךְ וְעַל דְּרָכֶיךָ נָגַהּ אוֹר.

Moses said to Hashem "But the Egyptians will hear that You have brought this nation out from its midst with great power.

  וַיֹּאמֶר משֶׁה אֶל ה' וְשָׁמְעוּ מִצְרַיִם כִּי הֶעֱלִיתָ בְכֹחֲךָ אֶת הָעָם הַזֶּה מִקִּרְבּוֹ

Bamidbar (14:13)

Since Moshe said in his prayer that there may be a desecration of the name of Hashem (ח"ו) if Yisrael would be annihilated. This is what Rashi means by  "Because of what you said, namely,'They might say that Hashem lacks the ability...'" It is as though Hashem is saying to Moshe that your concern of what the nations of the world would say is legitimate and has made a profound impression unlike if someone else would raise this issue, just as the verse says in Iyov - and light will shine on all your ways -  about the power of Tzaddik.