Is an increase in the value of loaned gold considered usury if its value rises significantly upon repayment?

Whoever borrowed gold must return an equal weight of gold. The difference in value does not affect this, nor is an increase in its value considered usury (riba). It is permissible to return its value in cash at the rate of the day of repayment, provided that this is by mutual agreement of both parties and the full price is paid, based on the Prophet's (peace and blessings be upon him) saying: "There is no harm in taking it at its day's price as long as you do not separate while there is still something between you," and his saying: "Gold for gold, weight for weight, like for like."