http://apologeticspress.org/AllegedDiscrepancies.aspx?article=672&b=Genesis
Canaanites Were in the Land…Then
by Eric Lyons, M.Min.
Have you ever wondered why, if Moses wrote the Pentateuch, in Genesis 12:6 and 13:7 the Bible says (in reference to the time of Abraham), “[T]he Canaanites were then in the land” (emp. added). If the Canaanites occupied the land of Canaan in Moses’ day, why would Moses write that they were in the land then (in the days of Abraham)? Would these verses not make more sense if we understood them as being written at a time when the Canaanites had been driven out of the land of Canaan (which was hundreds of years after the death of Moses)? According to several critics, this is exactly what the verses are implying (cf. Gottwald, 1959, p. 104; McKinsey, 1995, pp. 361-362). Supposedly, Moses could not have been the author of the passage; else it would not have made sense to its original audience.
The phrase “the Canaanites were then in the land” does not necessarily have to point to a time after Moses when the Canaanites no longer were in Canaan. When the careful student takes into consideration the context of these passages, and the momentous events of Abraham leaving his homeland and coming to the new region that his descendents one day would occupy, he or she easily can understand that the phrase in question refers to this land promise (12:7). The words “then in the land” merely are indicating “that the land into which Abram had come was not uninhabited and without a possessor; so that Abram could not regard it at once as his own and proceed to take possession of it, but could only wander in it in faith as in a foreign land (Heb. 11:9)” [Keil and Delitzsch, 1996]. Likely, the Canaanites are mentioned as being in the land at the time of Abraham’s entrance in order “to show the strength of his faith in the promise recorded” (Jamieson, et al., 1997). Such phraseology involves neither a contradiction nor an absurdity.
REFERENCES
Jamieson, Robert, et al. (1997), Jamieson, Fausset, Brown Bible Commentary (Electronic Database: Biblesoft).
Keil, C.F. and F. Delitzsch (1996), Keil and Delitzsch Commentary on the Old Testament (Electronic Database: Biblesoft), new updated edition.