As shrewd as snakes

Key verse
Matthew 10:16 - "I am sending you out like sheep among wolves.  Therefore be as shrewd as snakes and as innocent as doves."

Genesis
Jacob was probably one of very few Hebrews to be embalmed (chapter 50)!  I wonder if this process was strange to his family (excluding Joseph, of course).
Joseph's brothers had clearly not forgotten what they had done to Joseph so many years earlier.   Is there evidence that they had kept the true story from their father when they found out he was alive?  In any case, Joseph's forgiveness of his brothers is a good picture of the type of forgiveness we should bear toward one another, as it says in 50:21 "And he reassured them [his brothers] and spoke kindly to them."

The staff and salvation

Genesis
I was curious as to what Genesis 47:31 meant - "'Swear to me,' he [Jacob] said. Then Joseph swore to him, and Israel worshiped as he leaned on the top of his staff."  Particularly the part about the staff interested me.  What I found out was that out of 10 or so translations, the NIV was the only one that used 'top of his staff'.  The rest talk about the head of the bed.  However, the staff terminology comes from Hebrews 11:21 and the Greek version of the Old Testament, which makes more sense than the Hebrew version 'head of the bed'.  In fact, as I found out from the Jamieson-Fausset-Brown Bible Commentary, the bed likely didn't have have a 'head' as it was just a mat, so top of the staff makes more sense.  Clarke's commentary suggests that Jacob, in his old age, simply needed to lean on the staff for support, and he worshiped God because Joseph would be able to bring his bones back to his forefathers' resting place.

Matthew
In Matthew 9:13 Jesus says, "But go and learn what this means: 'I desire mercy, not sacrifice.' For I have not come to call the righteous, but sinners."
This verse reminds me that once we're saved, it's not the end.  Jesus was always looking to speak to the sinners, to rescue them and bring them into new life.  Once we've been rescued, we shouldn't sit on our laurels; we should go out and help Jesus extend God's kingdom on earth.

Loving our enemies

Genesis
It's interesting to see how the twelve tribes of Israel came about because two sisters were fighting over who got to sleep with their shared husband.  What a different culture!  With a more modern worldview, we can look at this story and say that it is clearly a lesson to not have two sisters marry the same man.  However, if we put ourselves in ancient Canaanite/Israelite history, we would find that this situation is more common than not.
As for Jacob being deceived by Laban, one can't feel too sorry for him, as he himself was a great deceiver (cf. Esau (twice!) and Laban's sheep).

Matthew
I've often wondered what was meant by Matthew 5:48 - "Be perfect, therefore, as your heavenly Father is perfect."  Read alone, it suggests that we need to attain perfection, not having any sin.  Read in context, "perfect" seems to suggest something a little more attainable (see the commentaries at http://bible.cc/matthew/5-48.htm).  Jesus was just talking about loving our enemies, not just our neighbours.  Just as God loves all people, and acts with a certain wholeness and consistency, so we must also be whole, complete, and consistent in our attitude, mirroring that of God the Father as represented through Jesus.