Abraham's heirs understand that God has promised them the Land of Canaan. Archaeology has demonstrated that Abraham is a quasi-fictional character and that some of the stories about him are false with no basis in fact, calling into question the alleged "Promised Land."
Based on the archaeological findings at Beersheba Abraham had been dead for over 1000 years when God made his promise to him in a "Philistine World." Ergo, the promise was _never_ made to the long-dead Abraham and neither Jew nor Moselm has any legitimate claim to the Promised Land as Abraham's heirs.
Read more interesting topic about archaeology excavations.