Is the mortgage of fruit from a tree bearing two harvests valid if the two harvests cannot be distinguished when the debt becomes due?

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The mortgage (*rahn*) of the first harvest of a tree that yields two indistinguishable harvests, when the second harvest is set to appear before the debt is due, is invalid. This is because the subject of the mortgage becomes unknown (*majhul*) upon the due date of the right, rendering it impossible to recover the debt from it. This invalidity mirrors the situation where the object is unknown at the time of contracting or if it was mortgaged after becoming indistinguishable. However, the mortgage is valid if a condition is stipulated that the first harvest must be cut if there is a fear of its mixing with the second.