Eshel (H812) refers to the tamarisk tree — a hardy desert shrub or small tree known for its feathery foliage and remarkable ability to survive in arid conditions. It appears 3 times in the OT. Abraham plants a tamarisk at Beersheba after making a covenant with Abimelech.
The tamarisk tree (eshel) becomes associated with the patriarchs and their covenant-marking practices. When Abraham plants an eshel at Beersheba and 'calls on the name of the LORD, the Eternal God' (Gen 21:33), the tree becomes a living memorial to YHWH's faithfulness. Similarly, Saul sat under a tamarisk at Gibeah (1 Sam 22:6). Trees serve as altars and memorials in the OT — their longevity marking the permanence of God's promises.
The tamarisk is one of the most drought-resistant trees in the Middle East, surviving on minimal rainfall through salt-secretion. Its feathery branches provide shade in harsh climates. Abraham's planting of an eshel at the well of Beer-sheba (the well of the oath) connects covenant, water, shade, and eternal God — a rich cluster of images for God's faithful provision in the wilderness of life.