Deutéronome 34:10

But no prophet hath again risen in Israel like unto Mosheh, because the Word of the Lord had known him to speak with him word for word,

I have already explained the term face to face [comment on 5: 4].

WHOM THE ETERNAL KNEW FACE TO FACE. “[This means] that Moses’ heart was familiar with Him and he spoke with Him whenever he wished, as it is stated, and now I will go up unto the Eternal; Stay ye, that I may hear what the Eternal will command concerning you.” This is Rashi’s language. But it is not correct, for in that case [if the verse extols Moses’ familiarity with G-d] it should have said, “who knew the Eternal face to face.” Rather, this is similar to the expressions: and I know thee by name; Yet Thou hast said: I know thee by name., Verse 12. The verse thus states that there hath not arisen a prophet since in Israel whom G-d so exalted as to communicate with him face to face. Similarly, Eternal, what is man that ‘vateida’eihu’ means “that You should bestow honor upon him by giving heed to him,” like What is man, that Thou shouldest magnify him? It is possible that [this is the intent of the verse]: because when two persons see one another face to face, they become acquainted with each other through that meeting, Scripture therefore says whom the Eternal knew face to face [indicating that G-d and Moses were like two people who know one another well; however, Scripture said only that G-d knew Moses, not vice-versa], since out of respect to the Most Exalted it did not want to mention that Moses also knew Him that way. Now, do not be surprised that Scripture speaks in praise of Moses saying, Whom the Eternal knew face to face, and it also states, And the Eternal spoke unto Moses face to face, and with reference to all Israel it is likewise stated [the very same praise], The Eternal spoke with you face to face! For there [in the case of all Israel] he explained out of the midst of the fire, meaning to say that they heard His voice out of the midst of the fire only, and they did not actually see His Presence. Similarly he explained, and upon earth He made thee to see His great fire, and thou didst hear His words out of the midst of the fire., 4:36.
And by way of the Truth, [the mystic teachings of the Cabala], the verse here states that G-d knew Moses face to face [to a degree that it was possible] to cleave to Him whenever the spirit came upon Moses our teacher. It was so at the time of the Giving of the Torah, but the people perceived only the Voice out of the midst of the fire. Thus Scripture explained that all prophecies of Moses were as on the day that the Torah was given, while the rest of the prophets had the hand of the Eternal upon them. Understand this.

ולא קם נביא עוד בישראל כמשה, no other subsequent prophet ever attained the lofty spiritual stature of Moses. This explained the statement by our sages that no prophet is allowed to innovate something in the Torah since Moses had died. (Shabbat 104) This statement also explains the rule that no Rabbinical assembly may invalidate a decree by another such Rabbinical assembly which had preceded it, unless it could be proven to be more competent and consisted of a greater number than the Rabbinical assembly which had originated said decree. (Megillah 20)