Genesis 21:33
31 That is why he named that place Beer Sheba, because the two of them swore an oath there. 32 So they made a treaty at Beer Sheba; then Abimelech and Phicol, the commander of his army, returned to the land of the Philistines. 33 Abraham planted a tamarisk tree in Beer Sheba. There he worshiped the Lord, the eternal God. 34 So Abraham stayed in the land of the Philistines for quite some time.
Deuteronomy 16:21
20 You must pursue justice alone so that you may live and inherit the land the Lord your God is giving you. 21 You must not plant any kind of tree as a sacred Asherah pole near the altar of the Lord your God which you build for yourself. 22 You must not erect a sacred pillar, a thing the Lord your God detests.
Notes and References
"... Although the rest of the Torah would not be intelligible without the background provided in the Book of Genesis, this work nevertheless constitutes a distinct and discrete unit within that literary corpus. Its individuality and antiquity are asserted in numerous ways: The Stone Pillar (matsevah) ... this cultic object is sternly forbidden in Leviticus 26:1 and Deuteronomy 16:21-22 as being abhorrent to God; yet the Genesis narratives do not hesitate to ascribe its use to the patriarch Jacob. It is clear that the texts were not altered to conform to the standards of a later age. The same conclusion may be drawn from the report about Abraham planting a tamarisk and engaging in worship at the site, an act prohibited in the legislation of Deuteronomy 16:21 ..."
Sarna, Nahum M Genesis: The Traditional Hebrew Text with New JPS Translation (p. xv) Jewish Publication Society, 1989