In the meantime, Sarah is blessed with her own child, Isaac, who she recognizes as a suitable torchbearer for Israel. Sarah ultimately banishes Ishmael, whose negative influence is a threat to Isaac's spiritual development. The longest discourse about Sarah concerns her death and burial. Such detailed treatment of this subject is unprecedented in Torah. In this case, however, the passage about Sarah's death and burial is the key that unlocks the essence of her greatness.
Jewish law is explicit about proper burial practices.
These rituals respect to the body, which is the tool a Jew uses in his or her lifetime to do the will of God. Sarah mastered the use of her body as a instrument of Hashem. That the Torah recounts Avraham's negotiation and purchase of the site where her body would rest implies its perfect utilization in her lifetime. Avraham knew that this energy was a fitting tribute to Sarah and was willing to go to great length and expense to procure it. The Torah tells us that he succeeded, thanks to Sarah's spiritual accomplishment in Egypt.