Musar על סנהדרין 219:5

Another difficulty is the Torah saying: "Moses heard and fell on his face" (16,4). Sanhedrin 110, asks what it was precisely that Moses had heard, and Rabbi Samuel son of Nachmeyni says that he had heard that these people suspected him of committing adultery, since we read in Psalms 106,16: "ויקנאו למשה במחנה," which is interpreted by Rabbi Shmuel bar Vitzchak that each Jewish husband suspected Moses of a adultery with his wife, since the Torah had stated that "Moses took his tent and put it up outside the camp" (Exodus 33,7). The question arises that even granted the Jewish people were sinful, how could they have suspected Moses of adultery?! After all, Miriam had criticised Moses for not even living with his own wife, much less with other husbands' wives! What possible reason could these people have had to suspect Moses of something so patently absurd? Many commentators have written that this accusation is not to be taken at face value, but rather that the rebels denied the quality of Moses' prophetic insights, claiming that it was not, as stated, of a פנים אל פנים variety as described in Deut. 34,10, i.e. qualitatively superior to the prophetic powers of other prophets. The rebels claimed that these other angels by means of whom prophetic images are transmitted are known as "אישים," "men," meaning that they are the means by which humans receive intelligence from celestial sources. The recipient would then be described as אשת איש, "a married lady", much as a wife describes herself as such, seeing she is the "passive" part of her husband. Their intention then was to deny Moses his special relationship with G–d. It was this special relationship which Maimonides describes. In his Moreh Nevuchim he describes the people protesting Moses' arrogant behavior in claiming special status!

I have mentioned already that at the beginning of his career Moses was on the level of איש. When a person is referred to as איש, this means that he is someone of substance. Later on Moses rose to higher levels and became אלוקים. In his Moreh Nevuchim, Maimonides explains this as follows: All the prophets receive their prophetic inspiration by means of a go-between, i.e. angels who are called אישים, because they are the medium through whom men are granted prophetic insights. This rule did not apply to Moses, however. Moses enjoyed direct inspiration. Maimonides goes on to explain the words of our sages on Numbers 16,4 where the Torah describes Moses as falling on his face after hearing the accusations of Korach. According to Sanhedrin 110, Korach accused Moses of adultery. This seems a very strange accusation, seeing that Moses had been faulted by his own sister for separating from his wife, abandoning marital life, due to his calling as a prophet who had to be "on call" at all times in case G–d wanted to communicate with him (Numbers 12). Why would Korach level such an unreasonable accusation against Moses?