Joseph harnessed his chariot and rode to Goshen toward his father; he showed himself to him, fell upon his neck, and wept… (46:29)

But Jacob did not embrace Joseph and did not kiss him; our sages tell us that he was reading the 'Sh'mah'.

- Rashi's commentary

Jacob knew that never in his life would his love be aroused as it was at that moment, the moment of reunion with his most beloved son after 22 years of anguish and loss. So he chose to utilize this tremendous welling of emotion to serve His Creator, channeling it to fuel his love for G-d.

- chassidic saying.

In 1892, Rabbi Sholom DovBer of Lubavitch presented his twelve-year-old son, Yosef Yitzchok, with the manuscript of a ma'amar (a discourse of chassidic teachings) entitled Moh Rabu Maasechah1and said: "This is a chassidic kiss. In time I will explain." Four years later, he related the following incident to him:

The year was 1884. Late one night, Rabbi Sholom DovBer was studying with Rabbi Jacob Mordechai Bezfolov. Rabbi Sholom DovBer's family then lived in two rooms: one served as the bedroom, the other, as Rabbi Sholom DovBer's study. In this room also stood the cot of his only child, the four-year-old Yosef Yitzchok.

Little Yosef Yitzchok was an extremely beautiful child with a delicate and radiant face. Rabbi Jacob Mordechai, enthralled by the sleeping child, commented that the radiance of the child's countenance must reflect an inner purity of mind.

Rabbi Sholom DovBer was moved by a strong desire to kiss his son. But at that very moment he thought of the gold and silver that were used to beautify theHoly Temple in Jerusalem, transforming physical substances into something holy and spiritual. He decided to direct his overwhelming feelings of love for his son into a more spiritual gift: he would give his son a ma'amar instead of a kiss. He sat down and wrote 'Moh Rabu Maasechah.'

FOOTNOTES
1. "How great are Your works…"