What do the respected Islamic scholars say about the following issue that a man sold a machine to another person for the price of eighteen thousand rupees. However, he was concerned that the buyer might not be able to pay on time, so he requested a guarantor, which was provided. Later, after the agreed-upon time had passed, the buyer indeed failed to pay the amount. In the meantime, three years went by.Now, the seller claims that since you did not pay the amount on time, the total has now reached three hundred thousand rupees. Therefore, he is demanding that you pay him three hundred thousand rupees and is asking the guarantor to make this payment.Is the seller's demand valid?
Is it permissible for him to charge three hundred thousand rupees instead of the original eighteen thousand?
In the case under discussion, both the buyer and the guarantor are obligated to pay only the amount that was agreed upon at the time of the contract. Although, due to the unjustified delay and causing distress to the seller, they are guilty of breaking a promise and causing harm, both of which are sinful, the seller’s demand for an amount exceeding the agreed price is not valid, and such a demand must be avoided.
کما قال اللہ تعالیٰ: ﴿يَاأَيُّهَا الَّذِينَ آمَنُوا لَا تَأْكُلُوا الرِّبَا أَضْعَافًا مُضَاعَفَةً﴾ (آل عمران: 130)۔