After years of separation, two brothers destined to lead the redemption of the Israelites reunite in the desert. This encounter represents a rare moment of pure brotherhood and precise divine orchestration. While Moses was in Midian, God spoke to Aaron in Egypt at the exact same moment, instructing him to go out and meet his brother [אור החיים, מלבי״ם]. This direct communication reveals that Aaron was a prophet in his own right [אור החיים]. His journey into the desert was the active fulfillment of the promise God had just made to Moses [רשב״ם, בכור שור].
Following God's instruction, Aaron traveled into the desert, meeting Moses halfway between Egypt and Midian [אברבנאל, קאסוטו]. Their paths crossed at the Mountain of God, identified as Mount Sinai or Horeb [רמב״ן, אבן עזרא, בכור שור, ביאור שטיינזלץ]. This specific location was divinely arranged rather than coincidental [קאסוטו, אלשיך]. It ensured that Aaron would join Moses at the very same holy site where the mission originally began at the burning bush [ברכת אשר].
The physical nature of their encounter was unique. Moses was so deeply immersed in solitary meditation and prophetic devotion on the holy mountain that he did not notice Aaron approaching until they physically bumped into one another [העמק דבר, אלשיך]. Furthermore, this comforting and positive reunion stands in sharp contrast to the immediately preceding events at the lodging place, where a divine encounter threatened Moses with death [צרור המור, קאסוטו].
Upon meeting, Aaron kissed his brother out of immense joy and deep love [בכור שור, שפתי כהן, ביאור שטיינזלץ]. Throughout biblical history, relationships between brothers, such as Cain and Abel, Isaac and Ishmael, Jacob and Esau, or Joseph and his brothers, were often filled with tension and conflict. Moses and Aaron, however, displayed pure brotherhood. They harbored no jealousy toward one another regarding their respective future roles in leadership and the priesthood [הדר זקנים].
The narrative specifically notes that Aaron kissed Moses, rather than describing a mutual embrace. One perspective attributes this to Moses' humility. Out of respect for his older brother, he refrained from initiating the physical greeting [רמב״ן, הטור הארוך, ביאור יש״ר]. Another approach views the kiss as a profound expression of Aaron's admiration. Recognizing Moses' superior spiritual elevation, Aaron approached him with the reverence of a student greeting a master [ספורנו], kissing him with the awe usually reserved for a holy object [ספורנו, העמק דבר].
This harmonious reunion is seen as the living embodiment of the concept that kindness and truth meet, while justice and peace kiss. Aaron, representing peace and kindness, joined with Moses, the man of truth and justice. Together, they united these essential traits to bring about the redemption of the Israelites [רבנו בחיי, הדר זקנים, חזקוני, מלבי״ם].