What is intended by these two reports, and by similar reports in which the Imam عليه السلام, peace be upon him, says that “he shortened at one farsakh,” is the following: When the intended journey has reached the distance at which shortening becomes obligatory, or exceeds it, and the traveller has already travelled for a day or more, then if he thereafter travels another farsakh or two farsakhs, shortening becomes obligatory upon him. This is because the overall extent of his journey has reached the required limit for shortening. The consideration is not merely the amount that the person travels at one time. Rather, consideration is given to the intended distance of the journey, even if he does not travel all of it in one stretch or in a single day. This interpretation is not contradicted by what he narrated (in the following hadith):
Commentary #9