The main question that Rashi is usually addressing with his comments is “Who Cares?”
In the Yosef episode we find this around every detail.

Yaakov sent Yosef to look for his brothers and the Torah says, “he sent him from the depths of Hevron and he arrived in Shechem.”

Rashi says that the depths of Hevron is inaccurate.  We know from later in the Torah that Hevron is on a mountain.  Rather, says Rashi, when the Torah says the depths of Hevron, it really means the profound council of the righteous Avraham who was told in a prophesy that his children would end up in a strange land.

Shechem also has deep symbolic meaning.  This was the beginning of the tragic Yosef story, and the name Shechem conjures up all of the other tragic episodes that happened in that very same city (until this very day, unfortunately).

Rashi comments because all of these details seem superfluous.  Who cares where he came from and where he was going?  In fact, he didn’t even find his brothers in Shechem.  he got lost in a field and ran into some random guy.

“A man discovered Yosef and he was blundering in the field; the man asked him, saying, “What do you seek?”

Rashi comments and tells us that this man was Gavriel the angel.

This is one of my favorite Rashi’s in the whole Torah.  Short and simple, but so profound.

Think about it.  If Yosef had not run into that “man” he never would have found his brothers.  he would have went back to his father, and the whole story never would have happened.  This man changed history forever.

It had to be either the angel Gavriel or Forest Gump.  Those are the only two people who can so innocently make such a big difference.

Actually, there are lots of Gavriel encounters that happen to people all the time.  I have had encounters with angels like that in my life.  I am sure everyone has.

A few passukim later Rashi says once again, “This verse says, ‘Darsheini!” expound me.”  I believe whenever Rashi says that he is not only talking about the one verse he comments on, but the whole section.

The word “Darsheini” from drash, means to seek.  When Rivka went to “search out Hashem” it uses the same word.  The word is not used here by Yosef, but the Torah may as well have used it.

“A man found him lost in the field and said to him, ‘What are you seeking?'”

Some of the most important points in my life were when I was stumbling in the field and it took a person, sometimes a person who didn’t even know me that well, to ask me flat out, “What are you seeking?”  They presented me with hard truths and they challenged me to get my act together and find direction.

The people who did that for me probably don’t even remember doing it, but I will never forget them.  They were angels sent from Hashem.

Yosef’s destiny was changed in an instant, and with it the destiny of the Jewish people.  Sometimes we meet Gavriel’s and sometimes we are Gavriels for other people and we don’t even know it.
I find this to be a very profound idea.