مَعَ العُسْرِ

مَعَ العُسْرِ is a phrase (شِبْهُ الجُمْلَةِ) consisting of a particle of pulling down (preposition) and a genitive noun

PhraseParticle / NounNoun Particle
شِبْهُ الجُمْلَةِجَارٌ وَمَجْرُوْرٌاسْمٌ مَجْرُوْرٌحَرْفُ جَرٍّ
PhraseCompoundGenitive NounParticle of pulling down
  
with hardshipمَعَ العُسْرِ=العُسْرِ+مَعَ 
along with hardshiphardshipaccompanied by, along with
Surah/Below are the 2 verses in the holy Quran containing the genitive compoundمَعَ العُسْرِ
Verse
94-5Surely, along with hardship is reliefفَإِنَّ مَعَ الْعُسْرِ يُسْرًا
94-6Surely, along with hardship is reliefإِنَّ مَعَ الْعُسْرِ يُسْرًا