المَرْحَمَةِ

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

الْمَرْحَمَةُ is the natural state of this indefinite noun and it becomes المَرْحَمَةِ 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

Compassion

To love, have tenderness, have mercy, pity, forgiveness, show goodness, favour, have all that is required for exercising beneficence

الْمَعْرِفَةُمُفْرَدٌمُؤَنَّثٌمَجْرُوْرٌر ح مبَاب سَمِعَالْمَصْدَرُ الْمِيْمِيُّمَفْعَلَةٌرَحِمَ يَرْحَمُاسْمٌالْمَصْدَرُ
DefiniteSingularFeminineGenitiveRootMercyPattern سNounVerbal noun
Surah/Below is the only verse in the holy Quran, containing the nounالمَرْحَمَةِ
Verse 
 
then he became of those who believed and recommended to patienceثُمَّ كَانَ مِنَ الَّذِيْنَ ءَامَنُوْا وَتَوَاصَوْا بِالصَّبْرِ
90-17and recommended to mercyوَتَوَاصَوْا بِالمَرْحَمَةِ