My contention is not with what is written.
If I borrow a tangible item from someone such as a quantity of food, or an article of clothing that I wear out then I must pay back what is borrowed.
Money is an abstract representation of such articles representing an amount of goods for the convenience of trade as a replacement to a barter system. It is not in itself tangible.
The holy words conveyed by the Prophet Muhammad (Sallallahu Alaihi wa Sallam) were given at a time when inflation was not an everyday matter.
How can it be just for me to take now what is worth 100 loaves of bread from a friend and pay him back twenty years later with what, for example, can only obtain 5 loaves. Surely I have not repaid what I have borrowed when I do this?
I can accept that changing the value through adjusting between the relative values different currencies would be fraught with problems, but in terms of value when we are dealing with the same currency it does not seem just.
Forgive me if I have not understood things as I should, but I need explanation and guidance this matter. No matter now eminent and blessed a temporal judicial assembly can still be fallible, unlike Allah Who knows best.

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

The Islamic Shariah is descended by Allah the All-Knower the All-Aware.  He made His Shariah to suit all periods and times, the Shariah, consists of only goodness and benefits for all people.

 In fact, inflation was not known during the period of the Prophet (Sallallahu Alaihi wa Sallam) but Allah who revealed His Shariah for human beings is well aware of inflation and the matters that will happen.

Know that the rulings of Shariah do not change and are not subject to any change.  The rulings of cutting the hand (from wrist) of a thief, lashing and excelling or stoning a fornicator or an adulterer, the prohibition of Riba and interest-based loans, and all other rulings of Shariah are the same as they were in the period of the Prophet (Sallallahu Alaihi wa Sallam). The factor of time has no effect on the rulings of Shariah.

Therefore, a Muslim should submit to the rulings of Shariah and follow them without any objection Allah Says (interpretation of meaning): {But no, by your Lord, they can have no Faith, until they make you (O Muhammad SAW) judge in all disputes between them, and find in themselves no resistance against your decisions, and accept (them) with full submission.}[4:65].

So, if one takes a certain amount one has to pay the same amount later regardless of the value of the currency whether it increases or decreases. It is also permissible to pay the equivalent of the same amount in another currency.  But taking more than the amount he had taken based on the value of the amount is not permissible since in this practice the lender of the money benefits while the purpose of loan in Shariah is to benefit the debtor but the lender gets the reward that will benefit him in the Hereafter. 

On the other hand, we do not claim that we are free from mistakes; we issue this Fatwa since it is the preponderant opinion that we adopt.

Do not forget that most of the time inflation is man made. Humanity is suffering for not following the ruling of Islamic Shariah.

Allah knows best.