فَإِنَّ مَعَ الْعُسْرِ يُسْرًا
For truly, with hardship comes ease. (الشرح: 5)
The fā shifts from the remembered favors to a consoling conclusion. Inna reinforces the assertion; maʿa al-ʿusr is an adverbial expression, and yusran is the delayed noun of inna in the standard grammatical analysis. Fronting the adverbial phrase and using an indefinite yusran highlight the ease that accompanies hardship.
Fā should not be restricted mechanically to immediate chronological succession. Here it can express consequence and explanatory connection. The proposition remains specific: ease accompanies hardship, and the reinforcing particle addresses the importance of accepting that assurance.