فِي العُقَدِ

فِي العُقَدِ 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
  
who binds (in knots)فِي العُقَدِ=العُقَدِ+فَي 
who binds (in knots)bindswho
Surah/Below is the only verse in the holy Quran containing the compoundفِي العُقَدِ
Verse
113-4And from the evil of the evil whisperers who binds (in knots)وَمِنْ شَرِّ النَّفَّاثَاتِ فِي العُقَدِ