The Michilta (Yisro,Parsha Alef) states that the one who initiated the embracing was Mosha, and thus the Rabbis learn that its proper for a person to honor ones in-laws........In the Shulchan Aruch (Yoreh Deah. Simon 240:Sif 24) it states that a man is obligated to honor ones father -in-law.......

A question can be asked, what is the significance in bestowing honor to ones in-laws? .......I would like to offer the following answer: In Genesis(3:12), when Adam is being approached by Hash. after eating from the tree, Adam says, "The woman whom You (G-d) had given to me, gave me of the tree and I ate.....

Rashi quotes from Avodah Zorah 5a, that Adam had denied the good (wife) that was given to him (adam) from G-d........" .......Adam had exhibited a blatant lack of gratitude for G-ds kindness, and in fact blamed G-d for his (adam) downfall.......

Mankind suffers from a perpetual condition of being ungrateful..........However, the Torah provides us with a solution to such a spiritual dilemma.........When Mosha bestowed honor to his father-in-law (Yitro), Mosha was in actuality rectifying Adams sin of ingratitude......By showing honor to Yitro, Mosha was actually grateful to Yitro for having raised a daughter who is now his (Mosha's) wife.........Adam wasn't grateful for G-ds kindness for providing him with a help mate, however Mosha was !!!!!!!

The Kabbalists write that in every moment of life a person must try to rectify the world so that the universe can come closer to its "Messianic End".......Perhaps a good start for such a rectification would be to develop a sense of gratitude ..............Perhaps our service to g-d and our relationship with others would dramatically improve for the better? Have a good Shabbos.......