Biblical symbolism of wheat

I was wondering if the use of wheat as the chosen crop the Covenant crew discovers was a nod to the biblical use of wheat?  Matthew 3:12 
New International Version
"His winnowing fork is in his hand, and he will clear his threshing floor, gathering his wheat into the barn and burning up the chaff with unquenchable fire."

Perhaps the wheat is symbolic of those David feels are substantial, useful, and valuable; hypocrites are as chaff, light and empty, useless and worthless. The text states that, "There is a day coming when the wheat and chaff shall be separated. The last judgment will be the distinguishing day, when saints and sinners shall be parted for ever." Was this depicted in the scene described by Cinemacon attendees where David drops the black substance on an unsuspecting civilization?