Shaykh Umar Farooq Saeedi
1960. Commentary: In this narration, the action of Uthman (radi Allahu anhu) is reported, that during his caliphate (after the initial six years), he began to perform the full four units (rak‘at) of prayer at Mina instead of shortening (qasr). Various reasons have been mentioned for this, but the real matter is that he performed the full prayer merely on the basis of permissibility (jawaz). That is why, for the first six years, he continued to perform qasr. And it was due to this very permissibility that Abdullah ibn Mas‘ud (radi Allahu anhu) also, in following Uthman (radi Allahu anhu), performed the full prayer and did not like to differ in this matter. Although he himself states that prior to this, he used to perform qasr. If performing the full prayer were not permissible, then certainly he would have differed and would not have considered differing to be a bad act, because if something is not permissible at all, then it is necessary to differ from it, and such differing cannot in any way be called a bad act. However, despite considering both qasr and completing the prayer as permissible for a traveler, he feared that in following Uthman (radi Allahu anhu), the four units he performed might not be accepted by Allah, so if even two units are accepted by Allah, that is a great thing, even if all four are not accepted. This statement of his is an expression of fear of Allah (khushiyyat ilahi) and the spirit of following the Sunnah, with which the noble Companions (radi Allahu anhum) were characterized.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 1960