مَمْنُوْنٍ

A word in the Arabic language will either be 1) a verb or 2) a noun or 3) a particle – مَمْنُوْنٍ is a noun

A noun may either be 1) Definite or indefinite 2) Masculine or feminine 3) Singular, dual or plural 4) Nominative, accusative or genitive

مَمْنُوْنٌ is the natural state of this indefinite noun and it becomes مَمْنُوْنٍ due to: 1) a preposition that precedes it or 2) a possessed noun that precedes it or 3) it’s a noun of dependent declension a) نَعْتٌ / صِفَطٌ adjectives b) التَّوْكِيْدُ emphatic c) المَعْطُوْفٌ conjunction d) البَدَلُ synonym

Diminish, Broken off

To fatigue, be gracious, reproach, lay under obligation

with عَلَى To be liberal, bestow a grace or a favour on any one, recount to one the benefits shown or to reproach him

The origin of it is to cut off: According to Raghib the grace cuts off the needs as one who receives benefits is no more a needy. Thus a kindness, grace or benefit cuts off the hunger. Al-Mannan الْمَنَّانُ The Great Benefector (Allah SWT)

 

Surah/Below are the 4 verses in the holy Quran containing the genitive nounمَمْنُوْنٍ
Verse
41-8
68-3and certainly, for you is a reward indeed, without endوَإِنَّ لَكَ لَأَجْرًا غَيْرَ مَمْنُونٍ
except those who believe and do good deedsإِلَّا الَّذِيْنَ ءَامَنُوا وَعَمِلُوا الصَّالِحَاتِ
84-25for them is a reward that will never endلَهُمْ أَجْرٌ غَيْرُ مَمْنُوْنٍ
95-6for them is a reward without endفَلَهُمْ أَجْرٌ غَيْرُ مَمْنُوْنٍ