Sforno on Exodus 4:27/ספורנו על שמות ד׳:כ״ז

1לך לקראת משה המדברה, like a student who walks some distance to welcome his teacher even before he arrives in town. The student is what we call the “reception committee.” Aaron being a student of Moses although he was his senior has been confirmed already in verse 16 when G’d told Moses concerning his brother: “you will be his prophet, i.e. mentor.”

2ויפגשהו בהר האלוקים. while Moses was already on his way back to Midian from his encounter at the burning bush, at the mountain of the Lord, all set to go to Egypt.

3וישק לו, as one kisses a sacred object. We find the term used in this sense in Samuel I 10,1 וישקהו, ויאמר הלא כי משחך ה' על נחלתו לנגיד, ”he kissed him and said: ‘the Lord herewith anoints you ruler over His own people.”