Celestial portents

Remarking on Joshua's Long Day in his recent commentary, Kenneth Mathews says:

The traditional view is that the sun stopped (i.e., the earth's rotation ceased), thus prolonging the sunlight of the day. The overthrow of the fleeing Amorites can be thoroughly complete if they cannot escape into the night…[But] the text itself does not support this view. Depiction of the sun "over Gibeon" and the moon "over the Valley of Aijalon" shows that the time of day must have been in the morning (10:12), not at midday, as this view assumes ("middle of the sky," 10:13). Gibeon and the Valley of Aijalon are on an east-west plane, meaning that with the naked eye the sun is seen in the eastern sky and the moon in the western sky. In astronomy this relationship is called "opposition." That two celestial bodies appear in the sky at the same time indicates that the time of day is morning.

The background to understanding the Joshua passage is the Assyro-Babylonian celestial omen texts…by studying the positions and movements of celestial bodies, diviners discerned messages from the gods regarding human events…For example, the celestial signs portended either good or ill for the king and the nation in battle. A propitious sign was when the first day of the full moon fell on the fourteenth of the monthly, at which time "opposition" of the moon and sun briefly occurred in the morning…On the other hand, if the opposition…appeared on another day (e.g. fifteenth day), the omen indicated disaster. 

Although the practice of celestial divination was widespread in the Late Bronze Age (a notable exception is Egypt), there is uncertainty about the extent to which Joshua and the Canaanites knew the technical art of celestial divination as conducted by trained scholars. Assyriologists are divided as to when and to what degree celestial omen calculation was current in Canaan during the Late Bronze Age. K. Mathews, Joshua (Baker Books 2016), 92-94.

That's a very intriguing interpretation. Mathews is not the first scholar to propose it. 

i) In its favor, it explains the significance of the implied celestial opposition. That's something a modern reader is apt to miss, which an ancient reader might pick up on. Although that identification depends on knowing the local geography. 

ii) However, I have reservations about that interpretation as stated. One difficulty, which commentators remark on, is whether the same sign would be viewed as a propitious omen for the Israelites but an unpropitious omen for the Canaanites. Perhaps, though, the idea is that this is polemical theology, which exploits the superstition of the pagan army–a view not shared by Joshua. 

iii) There's nothing extraordinary about that phenomenon. Doesn't opposition of sun and moon occur twice a month (once after dawn and once before dusk)? So how would that be an unparalleled day (v14)? 

iv) Likewise, the shifting position between sun and moon is periodic and predictable. Since the Canaanite army could presumably anticipate that phenomenon, why would they even engage the Israelite army if they regarded that, ahead of time, as a portent of disaster? 

v) Perhaps, though, what they saw was surprising and shocking. Maybe God produced an optical illusion, like a sundog, which defied their expectations. The perceived celestial opposition was not supposed to happen on that calendar day. And that happened in answer to prayer by the enemy. Their God caused it. If so, one can see how that would have a demoralizing effect on the Canaanite troops, leaving them in disarray. It would be like the "counterclockwise" effect of Ahab's sundial. They weren't just arrayed agains the Israelite army, but against the God of the Israelite army, who displays his terrifying power, in contrast to the impotent gods of Canaan. And that's in addition to the targeted hailstorm (v11). A God who can manipulated the forces of nature to shield his people and rout their adversaries.