لِرَبِّهِ

لِرَبِّهِ is a phrase (شِبْهُ الجُمْلَةِ) consisting of a genitive particle and a possessive nominal compound

PhraseParticle / Noun / NounNounNoun Particle
شِبْهُ الجُمْلَةِجَارٌ وَمَجْرُوْرٌ وَهُوَ مُضَافٌ وَ مُضَافٌ إِلَيْهِمُضَافٌ إِلَيْهِاسْمٌ مَجْرُوْرٌ وَهُوَ مَضَافٌحَرْفُ جَرٍّ
PhraseCompoundPossessive NounGenitive noun + Noun possessedParticle of pulling down
  
to his Lordلِرَبِّهِ=هِ+رَبِّ+لِ
to his Lordhislord ofto
Surah/Below are the 2 verses in the holy Quran containing the compoundلِرَبِّهِ
Verse
17-27  
100-6Truly, man is extremely ungrateful to his Nurturerإِنَّ الإِنْسَانَ لِرَبِّهِ لَكَنُوْدٌ