Vayakom Avraham me'al penei meto vayedaber el-bnei-Chet - Avraham rose from the presence of his dead, and spoke to the sons of Chet

The local inhabitants were members of the tribe of the Chittim.  The Torah had reported in Bereishit 10:15 that Chet was one of the sons of Kenaan.  All of the tribes residing in the land described as the "land of Kenaan," were sons of Kenaan, the grandson of Noach.

The unusual masculine construction in the words me'al penei meto instead of metah seeing that Sarah had been a female, the reason for this is the word guf (body) is masculine.  Now that Sarah had died, she was only a body.  The soul of a person does not die.  Hence, the word meto is absolutely appropriate here.