The root of the word RAHMAAN and RAHEEM is Ra-Ha-Meem (ر۔ح۔م). RAHIM or RIHM, means the womb i.e. the receptacle of the young in the belly where it is provided with the means of subsistence with tenderness and security, without it doing any endeavour. RAHMAH or RAHMAT has the following meanings: Mercy; Pity; Compassion; Tenderness; Beneficence; Pardon; Forgiveness; Favour; Sustenance; Means of subsistence; Plenty of herbage, or of goods, conveniences, or comforts of life.
From the study of the Quran, one can distinguish two different types of RAHMAH: Gratuitous and Earned. Gratuitous RAHMAH is the one that Allah has bestowed and bestows upon human beings without regard to their endeavours and deeds. The creation of the sun, the moon, the water, the air, and the earth and the sources of sustenance in it are examples of this kind of RAHMAH. The verses of the Quran which refer to this type of RAHMAH include: 7:57, 25:48, 27:63, 28:73, 30:46, 42:28. Earned RAHMAH is the one that Allah bestows upon human beings with regard to their endeavours and deeds. A paradisiacal life in this world and in the hereafter is an example of Earned RAHMAH, i.e. which is earned through effort and righteous deeds. The verses of the Quran which refer to this type of RAHMAH include: 7:156, 9:99, 12:56, 21:75, 21:86, 29:23, 45:30, 57:28.
Ar-RAHMAAN and Ar-RAHEEM are two different attributes of Allah and are not the repetition of the same attribute for the sake of emphasis. RAHMAAN: It is in the measure of fa’laan. It conveys the idea of fullness, extensiveness, and spontaneity and indicates the greatest preponderance of RAHMAH. RAHMAH associated with Ar-RAHMAAN comprehends the entire universe without regard to our efforts. The creation of the sun, the moon, the water, and the air etc. all are there because of this attribute. The attribute Ar-RAHMAAN generally pertains to this life, the creation of universe, sources of sustenance and so on. The attribute Ar-RAHMAAN is inseparable from the concept of Almighty (see 19:45, 36:11, 50:33). RAHEEM: It is in the measure of fa’eel. It conveys the idea of constant repetition and continuous manifestation of RAHMAH. RAHMAH associated with Ar-RAHEEM constitutes the liberal reward to those who seek it, strive for it and deserve it. It is the result of the actions of human beings. The attribute Ar-RAHEEM generally pertains to the life to come, comprising RAHMAH as a result of our good deeds. The attribute Ar-RAHEEM is separable from the concept of Almighty and indicates an aspect of activity.