Daat Zkenim on Leviticus
1 א

ויקרא אל משה. מדרש תנחומא לפי שהיה משה עומד בחוץ שהיה מתיירא לבא אל אהל מועד כי שכן עליו הענן אמר הקב"ה אינו דין שיהא משה עומד בחוץ מיד ויקרא אל משה ופרש"י לכל הדברות ולכל האמירות וגו' ועוד פרש"י יכול שמעו כל ישראל את קול הקריאה ת"ל קול לו קול אליו פי' לפירושו דכתיב בפרשת נשא וישמע את הקול מדבר אליו והיה לו לומר מדבר לו או עמו ומדכתב אליו משמע מיעוט לו' משה שומע ואין ישראל שומעין:

ויקרא אל משה, He (the Lord) called to Moses;” according to Tanchuma on this verse, G–d had to call out to Moses from inside the Hoy of Holies, (between the cherubs on the cover of the Holy Ark) as Moses at the time was standing outside the Tabernacle. He did so as He did not consider it fitting for Moses who had erected the Tabernacle to have to stand outside while His glory was inside. Moses had been afraid to enter as He had not been invited to do so, as long as the cloud was resting above the Tabernacle. Rashi adds that an additional reason for G–d calling to Moses first before speaking to him, was that this was also so when He completed speaking to him. The absence of any word indicating this, is that G–d, when having completed what He had to say, did not do so by anything indicating this. Furthermore the word לו, “to him,” which is really not necessary, was to teach that while Moses heard the call while standing outside, the people did not. In Numbers 7,89, at the end of the consecration of the Tabernacle, the Torah elaborates by writing that Moses heard the sound of G–d’s voice emanating from between the cherubs on the Holy Ark. The word אליו, “to him,” there makes it clear that only he heard that voice.