Seforno: It implies that Moshe was different than all other prophets, inasmuch as he prophesied with the Name of Hashem even whilst he was awake. ¹

Ramban (in Pasuk 6): It means that, as opposed to other prophets, who prophecy by means of dreams (which require interpretation), Moshe sees everything clearly and understands automatically everything that he sees.

R. Bachye #1: It means that he is like a member of the family, who comes (to speak with Hashem) and goes whenever he pleases.

R. Bachye #2 (according to Kabalah): It means that, unlike Adam ha'Rishon, ¹ he was not guilty of Kitzutz Netiyos.

R. Bachye #3 (according to Kabalah): "Beisi" is synonymous with the 'Beis of Bereishis', which is equvalent to the house of Tefilah. ²

Rashbam: It means that Moshe is always available, at any time of day. ³

Hadar Zekenim (in Pasuk 6) #1: It means that everyone knows that he is reliable ⁴ since He speaks to him directly, and not by means of riddles.

Moshav Zekenim and Hadar Zekenim (in Pasuk 6) #2: They maintained that Moshe should marry a woman with good lineage. Hashem replied that he married when he was a shepherd, and did not want to divorce her now that he was king, because he was loyal.

Targum Yonasan: It means 'In all the house of Yisrael My people he is trustworthy'. ⁵

Oznayim la'Torah: With reference to the Mishkan, it means that, as opposed to Aharon, who is permitted to enter the Kodesh, but not the Kodesh Kodshim, ⁶ Moshe may enter anywhere, even the Kodesh Kodashim, whenever he pleases. ⁷