2/196 — The pilgrimage: a licence set beside the ruling
"Complete the pilgrimage and the ʿumra for God. If you are prevented, then send whatever offering is within your means…"
وَأَتِمُّوا۟ — itmām: to finish without shortfall a work that has been begun. The command is not "do" but "complete". The subject, that is, is that a thing begun should not be left half done.
فَإِنْ أُحْصِرْتُمْ — root ح-ص-ر: to surround, to hem in and cut off the way. Ḥaṣr (restriction) and muḥāṣara (siege) are from the same root. The verb comes in the passive: who does the preventing is not said — illness, an enemy, a road closed; all fall within the scope.
The characteristic of the section is at work here too: as the ruling is laid down, its exception is given inside the same verse. What was done for fasting at verse 185 is done here for the pilgrimage.
And the ransom is given with three options: fasting, alms or an offering. The choice is left to the person — he does whichever is within his means. That the ruling is not locked to a single form is the practical counterpart of the clause "God wants ease" at verse 185.
لِمَن لَّمْ يَكُنْ أَهْلُهُۥ حَاضِرِى ٱلْمَسْجِدِ ٱلْحَرَامِ — to whom the licence belongs is limited by geography: to those who come from afar. One who lives nearby can come at any time in any case. The ease is given where the hardship is.