An Altar or a Tree?

So they made a covenant at Beersheba; and Abimelech and Phicol, the commander of his army, arose and returned to the land of the Philistines.  Abraham planted a tamarisk tree at Beersheba, and there he called on the name of the LORD, the Everlasting God.  And Abraham sojourned in the land of the Philistines for many days. (Genesis 21:32-34 NASB)

In a few locations (precisely 3) Abraham builds an altar on a spot where God speaks to him.  One is Shechem, one is at Bethel, and the third is in Hebron.  He has been to the Negev before, and from what I hear, there are plenty of rocks with which to build an altar, but he doesn't.  Here, Abraham plants a tree, a shade tree, and calls on the name of Yahweh, El Olam.  Why the tree and not a stone altar?

In this place, Abraham has found an unexpected pocket of righteousness in Abimelech and his people (except for the grumpy shepherds who stole his well).  Here God spoke on his behalf to the king and Sarah is protected and Abraham rewarded (for lying, but that's a previous entry).  In this place Isaac is born, circumcised, and weaned.  And, most recently, Abraham buys a well back.  So why the tree?

It's the desert.  One typical characteristic of deserts is the lack of trees.  When they are seen, it usually means the presence of a spring or oasis.  To desert folk of nearly any culture, they represent life.  But there are desert trees that do not necessarily mean water or a spring.  Tamarisk trees do well in deserts and can be found on three different continents and wide varieties of deserts, from high to valley deserts.  In the US, they can be found in West Texas, New Mexico, and Arizona.  They are present in the Sahara of Africa, the Arabian Desert of the Arabian Peninsula, and in the southern wilderness of Palestine. 

Found at this website

When my oldest sister was married, she and her husband planted a "Silver Dollar Eucalyptus Tree" at the church.  It lasted many years (not as long as their marriage, they're still going!), and was a growing thriving reminder of their relationship.  I think the tree serves a similar purpose here.  It isn't that uncommon in the desert, it doesn't necessarily mark water or refer to "life", rather it marks a meaningful event in the life of Abraham.  That location became a place of meaning for him.  Rather than an altar of stone, he plants something that the Philistines would not have considered remarkable.  It wasn't a symbol for them, it was for him.  For them it marked his well?  Possibly.  But for him it marked a place where he met and received from his God.

Where is my "tree"?  Where would I plant them if I were to follow this practice?  Where has my Master fulfilled His promises to me, protected me, blessed me?  Where have I "redeemed a well"?  There are several places for me that fit this description, but the most recent is here in Northern Nevada.  I would have to be blind and foolish beyond description not to notice how clearly I have been led here, established here, and blessed here.  It's really amazing to review.  I am still experiencing blessing and the presence of my Master.  Ironically, I'm in the desert too.  I could plant a tree, and a Tamarisk might do really well here.  I wonder where I could find one.