Is an agreement to sell two measures of straw for four measures of straw considered usury, given the difference in the price per measure between the time of sale and the harvest season?

There is no objection to selling hay at a profit, as it is not one of the usurious commodities in which profit is prohibited. Accordingly, there is no objection to selling "2 shills" of hay for four, whether immediately or on credit, regardless of whether the four are equal in value to the two at the time of sale, or more, or less, based on the Almighty's saying: ﴿O YOU WHO HAVE BELIEVED, DO NOT CONSUME YOUR WEALTHS AMONG YOURSELVES UNJUSTLY, BUT ONLY [IN LAWFUL] TRADE BY MUTUAL CONSENT FROM YOU﴾ and His saying: ﴿AND ALLAH HAS PERMITTED TRADE AND HAS FORBIDDEN INTEREST.﴾