Or HaChaim on Genesis 23:4/אור החיים על בראשית כ״ג:ד׳

1 גר ותושב אנכי. "I am a stranger and resident. Abraham's description of his legal status is based on Maimonides Hilchot Zechiyah U-matanah 3,11: Whereas one must not give a gift to an idolator, one may either give a gift or sell to a resident stranger (גר תושב) because the Torah writes: "the resident stranger let live by your side" (Leviticus 25,35). We need to appreciate that our holy Torah applies reason, and especially so in our conduct on this earth. Just as we Jews are commanded to deal with resident strangers in a humane manner, so reason dictates that people all over the earth should conduct themselves with one another in a like manner. It is a universal obligation to enable resident strangers to live undisturbed and to be able to receive gifts. It is this principle Abraham alluded to when he said: גר ותושב אנכי תנו לי, "since I am a resident stranger, give me, etc." He made a point of using the word גר, alien, not just תושב, resident, in order to emphasise that though he was an alien, the fact that he resided amongst them entitled him to what he requested. There is a spiritual dimension to Abraham describing himself as an alien. He did not consider it seemly for a human being to describe himself as a "resident" on this earth, seeing that he looked forward to a permanent status in another, higher life.

2ואקברה מתי מלפני, "so I may bury my dead one from before me." Abraham meant that he wanted to bury Sarah without delay. Furthermore, Abraham knew already that he would have to pay Efron a substantial price for a field not worth a fraction of the asking price, because it contained something he wanted. At the same time, he realised that once the local people would hear of the price he was prepared to pay they would conclude there must be a hidden treasure beneath that field that they did not know about. In order to forestall such speculations by the local population he emphasised already at this stage that he was only concerned with burying Sarah forthwith i.e. מלפני, and that because of the urgency of the matter he could not afford to haggle over the price. Under such circumstances, it did not matter how much he would have to pay, the locals would not mind and would not suspect him of ulterior motives.