"God does" vs "God tells Moses to do"

Question

In the Torah, God frequently makes miracles happen either by doing them Himself, or by telling Moses to start them. Examples of the latter are telling Moses to throw a piece of wood in the water to make it drinkable, to strike a rock or talk to a rock to make water come out, to lift up his arm to make the sea split or make Amalek lose, etc. Also, God-commanded gestures by Aaron started many of the ten plagues upon Egypt.

What is the reason for the two different approaches? Do the commentators cover that point?

Answer 1

Bava Metzia 86b

אָמַר רַב יְהוּדָה אָמַר רַב: כׇּל מַה שֶּׁעָשָׂה אַבְרָהָם לְמַלְאֲכֵי הַשָּׁרֵת בְּעַצְמוֹ – עָשָׂה הַקָּדוֹשׁ בָּרוּךְ הוּא לְבָנָיו בְּעַצְמוֹ. וְכׇל מַה שֶּׁעָשָׂה אַבְרָהָם עַל יְדֵי שָׁלִיחַ – עָשָׂה הַקָּדוֹשׁ בָּרוּךְ הוּא לְבָנָיו עַל יְדֵי שָׁלִיחַ. ״וְאֶל הַבָּקָר רָץ אַבְרָהָם״, ״וְרוּחַ נָסַע מֵאֵת ה׳״. ״וַיִּקַּח חֶמְאָה וְחָלָב״, ״הִנְנִי מַמְטִיר לָכֶם לֶחֶם מִן הַשָּׁמָיִם״. ״וְהוּא עֹמֵד עֲלֵיהֶם תַּחַת הָעֵץ״, ״הִנְנִי עֹמֵד לְפָנֶיךָ שָּׁם עַל הַצּוּר [וְגוֹ׳]״. ״וְאַבְרָהָם הֹלֵךְ עִמָּם לְשַׁלְּחָם״, ״וַה׳ הֹלֵךְ לִפְנֵיהֶם יוֹמָם״.

Rav Yehuda says that Rav says: Every action that Abraham performed himself for the ministering angels, the Holy One, Blessed be He, performed Himself for Abraham’s descendants. And every action that Abraham performed through a messenger, the Holy One, Blessed be He, likewise performed for his descendants through a messenger. The Gemara elaborates: With regard to Abraham, the verse states: “And Abraham ran to the herd” (Genesis 18:7), bringing the meat himself, and in reference to God’s actions for Abraham’s descendants the verse states: “And there went forth a wind from the Lord, and brought across quails from the sea” (Numbers 11:31), that God brought meat to them. In reference to Abraham, the verse states: “And he took curd and milk” (Genesis 18:8), and God says to the Jewish people: “Behold, I will cause to rain bread from heaven for you” (Exodus 16:4), which shows that God gave food to the Jewish people. With regard to Abraham, the verse states: “And he stood by them under the tree, and they ate” (Genesis 18:8), and in reference to God, the verse states: “Behold, I will stand before you there upon the rock in Horeb; and you shall strike the rock, and there shall come water out of it” (Exodus 17:6). In the case of Abraham it is written: “And Abraham went with them to bring them on the way” (Genesis 18:16), and the verse states: “And the Lord went before them by day” (Exodus 13:21). By contrast, Abraham performed certain actions through an agent. He said: “Let now a little water be fetched” (Genesis 18:4), and correspondingly the verse states in reference to Moses, God’s messenger: “And you shall strike the rock, and there shall come water out of it, that the people may drink” (Exodus 17:6).

Answer 2

Rabbi Pinchas Horowitz, the Baal Haflaah, explains in the Haggadah by the phrase "I and not an angel", that there are two redemptions - outer and inner. The outer redemption was the physical freedom from slavery, and this was given to Moshe. The inner redemption was the redemption from idol worship; Hashem Himself had to work on the inside of the Neshamot of Benei Yisrael to redeem them from this.

This is a general theme - sparks can only actually be rescued by Hashem Himself. We do the work, but the actual extracting of the spark from the klipa is beyond our power and is only in the power of the One Who is above, and the Master of Good and Evil, i.e. the "Ba'al HaRatzon" - Hashem Himself.