This is an article in the chapter Probable Enormities from the classical manual on Sharia called Reliance of the Traveller. The articles are posted one by one in the order they are given in the book.
p75.0 PROBABLE ENORMITIES
(n: Commentaries by Imam Nawawi and ‘Abd al-Ra’uf Munawi have been added by the translator to some of the following hadiths.)
p75.1 The Prophet (Allah bless him and give him peace) said:
(1) “Beware of envy, for envy consumes good works as fire consumes wood.”
(2) “None of you believes until he loves for his brother what he loves for himself.”
(Nawawi:) It is fitter to interpret this hadith as referring to universal brotherhood, including both Muslims and non-Muslims, such that one loves for one’s non-Muslim brother what one loves for oneself, i.e. to enter Islam, just as one loves one’s Muslim brother to remain in Islam, this being why it is desirable (mustahabb) to pray for the guidance of non-Muslims. The hadith is understood as denying that someone who does not love for his brother what he loves for himself has perfect faith, love meaning to want what is good and advantageous for him, referring to religious love, not individual human love. For one’s human nature might well dislike another’s attaining the good, or surpassing oneself therein, though it is obligatory for one to resist this human tendency and pray for one’s brother and desire for him what one desires for oneself. Someone who does not love for his brother what he loves for himself is envious. and envy, as Ghazali notes, is of three types (A: all of them unlawful). The first is to wish that another person cease to have something good in order to obtain it oneself. The second is to wish that another lose something good, even if one does not obtain it, as when one already has another like it, or does not want it, this being worse than the previous type. The third is when one does not wish that the other cease to have something good, but resents his having surpassed one in attainment or position, accepting his parity with one but not his superiority. And this is unlawful as well, because one thereby objects to Allah’s division of His favor among His servants. Allah Most High says:
“Are they the ones who apportion the mercy of your Lord? It is We who have divided their livelihoods between them in this life, and raised some of them in degrees above others” (Koran 43:32).
So whoever does not accept this division opposes Allah Most High in His apportionment and His wisdom. One must remedy one’s human nature, make it accept destiny, and resist it by praying that one’s enemy be given what one’s self-interest might prefer him not to have (al-Arba’un al Nawawiyya wa sharhuha (y103), 40).