والثاني يوجب صحتها من أحد الطرفين، وهو استعارة الأصل للفرع
The second pattern is valid only in one direction: borrowing the term of the original case for the derivative case.
The original denotes the primary legal matter; the derivative denotes a related but distinct legal effect. Their relation is not strong or symmetric enough to let each expression replace the other indiscriminately.
The relevant test is whether the original expression is being used for a dependent consequence, and whether the proposed reverse transfer has a separate, valid justification.