because some scholars maintain that a truce with the disbelievers is permissible only for ten years or less; anything longer than that is not permissible.

Their evidence is that the Prophet ﷺ made peace with Quraysh for a period of ten years. They say: the basic principle is the obligation to fight and wage jihad against the disbelievers, so we may depart from this principle only to the extent established by the sunnah. The sunnah established ten years, so we may not exceed it. If the period exceeds this, the additional period is invalid.

It was also said that the entire contract is invalid. This is based on the issue of splitting a transaction, discussed in the Book of Sales.

If a person sells something that may be sold along with something that may not be sold, is the sale invalid in its entirety, or only with respect to what may not be sold?

The answer is: only with respect to what may not be sold.

For example, if he sells a slave and a free person, or sells his own car together with his neighbour’s car when his neighbour has not authorized him, the sale of his own car is valid, but not that of his neighbour’s car.

It was also said that the entire sale is invalid.

The madhhab is that there is no objection to extending the period beyond ten years if there is a need for that. The Prophet ﷺ set the period at ten years because he saw that this was sufficient, and that the Muslims would grow stronger and their strength would increase during that time. Thus, the specified period was not due to any special status of that particular length, but rather was determined by need.

According to the madhhab, therefore, it is valid for it to be temporary even for twenty years, thirty years, or more, if the need calls for it—for example, if the Muslims know that they are weak and will be unable, within five years or ten years,