لِلْعُسْرَى

لِلْعُسْرَى is a phrase (شِبْهُ الجُمْلَةِ) a compound consisting of a particle and a genitive noun

PhraseParticle / NounNoun Particle
شِبْهُ الجُمْلَةِجَارٌ وَمَجْرُوْرٌاسْمٌ مَجْرُوْرٌحَرْفُ جَرٍّ
PhraseCompoundGenitive NounParticle of pulling down/preposition
  
to difficultyلِلْعُسْرَى=العُسْرَى+لِ
towards difficultydifficultytowards
Surah/Below is the only verse in the holy Quran containing the phraseلِلْعُسْرَى
Verse
92-10then We will facilitate him towards difficultyفَسَنُيَسِّرُهُ لِلْعُسْرَى