12. And He said, "For I will be with you, and this is the sign for you that it was I Who sent you. When you take the people out of Egypt, you will worship God on this mountain."
13. The Lord said to Moses, "Rise early in the morning and stand firm before Pharaoh, and say to him, 'So said the Lord, the God of the Hebrews, "Let My people go so that they may worship Me.
3. Moses said to the people, "Remember this day, when you went out of Egypt, out of the house of bondage, for with a mighty hand, the Lord took you out of here, and [therefore] no leaven shall be eaten.
Talmud, Pesachim 116b
A person is obligated to see himself as if he were leaving Egypt
(ו)... כִּ֚י בְּצֶ֣לֶם אֱלֹהִ֔ים עָשָׂ֖ה אֶת־הָאָדָֽם׃
(6) ... man is made in the image of G-d.
Rambam, Mishnei Torah, Laws of the Foundations of Torah, 1:7
This God is one. He is not two or more, but one, unified in a manner which [surpasses] any unity that is found in the world; i.e., He is not one in the manner of a general category which includes many individual entities, nor one in the way that the body is divided into different portions and dimensions. Rather, He is unified, and there exists no unity similar to His in this world.
If there were many gods, they would have body and form, because like entities are separated from each other only through the circumstances associated with body and form.
Were the Creator to have body and form, He would have limitation and definition, because it is impossible for a body not to be limited. And any entity which itself is limited and defined [possesses] only limited and defined power. Since our God, blessed be His name, possesses unlimited power, as evidenced by the continuous revolution of the sphere, we see that His power is not the power of a body. Since He is not a body, the circumstances associated with bodies that produce division and separation are not relevant to Him. Therefore, it is impossible for Him to be anything other than one.
The knowledge of this concept fulfills a positive commandment, as [implied byDeuteronomy 6:4]: "[Hear, Israel,] God is our Lord, God is one."
ואומר (שמות לב טז): "והלחת מעשה אלהים המה והמכתב מכתב אלהים הוא חרות על הלחת", אל תקרא חרות אלא חֵרות, שאין לך בן חורין אלא מי שעוסק בתלמוד תורה.וכל מי שעוסק בתלמוד תורה הרי זה מתעלה, שנאמר (במדבר כא יט): "וממתנה נחליאל ומנחליאל במות".
It says (Exodus 32:16): And the tablets are the work of G-d, and the writing is G-d's writing, engraved on the tablets; read not "engraved" (charut) but "liberty" (chairut) --- for there is no free individual, except for he who occupies himself with the study of Torah.