Exodus 4:16 is typically translated as something like
"Moreover, he shall speak for you to the people; and he will be as a mouth for you and you will be as God to him." (NASB 1995)
Yet, Bill Schlegel in John 1:1 is parallel to the man Moses? says
"Now, most English translations put in the word “as” in translating God’s declaration: “you shall be as God to him”. But the Hebrew of this verse וְאַתָּ֖ה תִּֽהְיֶה־לּ֥וֹ לֵֽאלֹהִֽים does not have the word “as” in it. The more literal translation is “You will be God to him” (cf. Exo. 29:45; Jer. 24:7, 32:8; Eze. 34:24; Zec. 8:8)."
There is obviously a discrepancy between what Schlegel is saying and what the standard translation is of Exodus 4:16, although Schlegel wouldn't disagree about the intended sense of 4:16 - Moses isn't literally God.
The Keil and Delitzsch Biblical Commentary on the Old Testament also drops the 'as' in commentary on Exodus 4
""Put the words" (sc., which I have told thee) "into his mouth;" and I will support both thee and him in speaking. "He will be mouth to thee, and thou shalt be God to him." Cf. Exodus 7:1, "Thy brother Aaron shall be thy prophet." Aaron would stand in the same relation to Moses, as a prophet to God: the prophet only spoke what God inspired him with, and Moses should be the inspiring God to him. The Targum softens down the word "God" into "master, teacher." Moses was called God, as being the possessor and medium of the divine word."
Here repeatedly they talk of Exodus 4:16 as if the 'as' does not exist.
The article Was Moses “a god”? Exodus 4:16 and 7:1 talks a bit more about the specifics of the Hebrew.
"The Hebrew word translated “as” is the particle le (pronounced “luh”). Although the particle could simply mark the words “mouth” and “God” as direct objects of the repeated verb “shall be,” in context it may be taken as expressing comparisons."
So it sounds like the original Hebrew is ambiguous in terms of how to understand the word typically translated as 'as' here.
What are the grammatical and contextual arguments for and against adding an 'as' in Exodus 4:16's "you will be (as) God to him"?