NOTES for Gen 23:1-20
A cave for a tomb has been quite an ordinary thing in Palestine at all times. In the soft local limestone it is not hard to make even an artificial cave if no natural one is found. Besides, the "sons of Heth" offer Abraham a cave for free. Here, of course, before us, among other things, is traditional Eastern bargaining - "I give it for free" - "no, I will pay" - "dear friend, take it as a gift!" - "why as a gift?" - "is what you are offering even money?" - "well, take it anyway!" - "all right, I accept; the cave is yours!" Such bargaining is ordinary in the East; no transaction is concluded there without it.
The Abraham of the Bible is a man of his time and his country. Although it is possible that they really were offering him a cave for a tomb as a gift. After all, Abraham already enjoyed a certain authority among the neighboring tribes. It is hard to say which "Hittites" are meant here. They may have been actual Hittites, or they may have been some other Asia Minor tribes of Aryan origin. Several centuries before Abraham appeared in Palestine, it had for a time been part of the Hittite Empire, and some tribes that had inhabited it may have settled here, adopting the semi-nomadic way of life that all the local inhabitants practiced there. Judging by the story of Abraham's purchase of the cave, they deeply respected him, although his relations with other tribes, especially in Samaria, were more tense.
And yet even with the best relations, accepting such a gift would have been rash. Gifts created obligations, and relations could later change. Meanwhile, accepting such a gift meant binding oneself with obligations that were at least allied, if not directly vassal. When relations were good, one might not be reminded of this, but when they were bad... A purchase was more reliable: it implied complete independence from the seller, which in any case could not exist in relations with a giver. Abraham, however, had come to become master of the land, not subject to someone on it. He does not want to begin his life there with a loss of independence, even a potential one. And he buys a tomb for Sarah - taking root in the land promised to him by his God.