In Parashat Vayikra 1:1 says: " וַיִּקְרָ֖א אֶל־מֹשֶׁ֑ה וַיְדַבֵּ֤ר יְהֹוָה֙ אֵלָ֔יו מֵאֹ֥הֶל מוֹעֵ֖ד לֵאמֹֽר׃ - G-d called to Moshe and spoke to him from the Tent of Meeting, saying" The word I want to discuss today is the word Vayikra - And He called, which for some odd reason has a small Alef at the end of the word. Why is there a small letter Alef? Why isn't it the same size as other letters?
Please allow me to state my opinion of why what is about to follow may be the reason why the small Alef is present in this word. So with your permission, let's begin.
I believe the reason the small Alef is written is that Moshe Rabbenu learned and mimicked it from the moon.
Please allow me to explain.
In Masechet Chullin 60b:2-4 says: "Rabbi Shimon ben Pazi raises a contradiction between two verses. It is written: "And G-d made the two great lights" (Genesis 1:16), and it is also written in the same verse: "The greater light to rule the day, and the lesser light to rule the night," indicating that only one was great. Rabbi Shimon ben Pazi explains that "When G-d first created the sun and the moon, they were equally bright. Then, the moon said before the Holy One, Blessed be He: Master of the Universe, is it possible for two kings to serve with one crown? One of us must be subservient to the other. G-d therefore said to her, to the moon: If so, go and diminish yourself."
And based on this story, Moshe Rabbenu felt he needed to write the Alef in a smaller size, not the same size as the other letters.
And this is where the mistake was made, I believe.
If you have read the following essay, The "Well-Meaning" Inlaws, you will see how Yitro, the father-in-law of Moshe Rabbenu, just by being at the party, has caused Moshe to suddenly act weird - Moshe started serving people at the party, walked around with a tray, and started giving out food to the people. This behavior, as I have explained in that essay, was due to his past and unresolved trauma that he went through while he lived in the house of Yitro.
To undo the damage, Hashem has worked on Moshe day and night.