About the day of resurrection and bounties which will be granted to practicing Muslims, the Quran says: "But give glad tidings to those who believe and work righteousness, that their portion is Gardens, beneath which rivers flow. Every time they are fed with fruits therefrom, they say: "Why, this is what we were fed with before [but these are quite better] and they have therein companions pure (and holy); and they abide therein (for ever)" [1]
Here as in many other verses, faith and good deeds are introduced as two values which should always go together and accompany, none of which suffices alone. In other words, it can be said that the relation between faith and good deeds is similar to the relation between the spirit and the body and God will accept only those deeds which emanate from faith in Him, otherwise it is worth nothing spiritually. Moreover, faith not leading to good deeds has no value as faith without good deeds is unable to bring salvation to man.
For more information concerning the reality of faith and if good deed is part of the concept of faith or it has another reality, see: The Concept of Faith, 120, Degrees of Faith, 26716
Anyway, in this verse, God gives glad tidings to those with both faith and good deeds that they will receive four heavenly bounties. The nature of heavenly bounties is not clear for us. However, to have a relative understanding and a perspective, heavenly bounties have been compared to bounties in this world which is stated in terms comprehensible for us.
These four bounties stated as the reward for faith and good deeds are:
1-Gardens with rivers under their trees:  Flow of water not only irrigates trees, plants and flowers, it is pleasant to the eyes of beholders. This pleasure exists in heaven as well.
2-Heavenly fruits: Dwellers of heaven will have different fruits. A characteristic of heavenly fruits is that they do not have low quality kind. They have the same color, taste and size and no one can be preferred; so each time dwellers of heaven have fruits they say it is the same [fruit] they had before. They are given similar fruits.
3- Pure spouses: In the heaven people will be granted wives who are pure and sinless. Man will take great pleasure seeing them and living with them. These are the same houris [beautiful virgins] stated in other verses. See: Houris and marriage, 789; Houris for intimates and companions of the right hand, 36835
4- Eternity: In the heaven, each bounty even an important one, is worth nothing if it is not permanent and man will be upset to lose it although he has it for some time. Pleasure of having a bounty is not worth the agony after it is gone. However, bounties in heaven are eternal so this fact doubles the pleasure[2].
For the phrase "They say: this is what we were fed with before", interpreters have offered some probabilities:
1-Since fruits of heaven, although picked from trees, will grow again by divine will. So based on this principle dwellers of heaven will be boggled when they have a fruit and see it return to its place and they say in surprise it is what we have been granted before[3].
2- This verse means they have been granted these bounties before (in this world)[4].
3- This verse means: these fruits are similar to fruits we have been granted before in heaven. In other words, they know these new fruits are different from fruits in the past. But since they have the same color, taste, smell and indescribable quality, they are likened to fruits in the past[5].
However it is not impossible to accept all these interpretations together; since quranic terms have different esoteric meanings. It has been discussed earlier that a term can be used in more than one meaning which is in no way problematic[6].
The phrase "for they are given things in similitude" has some interpretations as follow:
1- Fruits of heaven have the same color but they have different taste[7].
2-All fruits of heaven are of similarly high quality. There is no low quality fruit among them[8].
3- Some fruits of heaven are similar to fruits in this world. However, fruits of heaven are better and they smell better[9].
4- Due to resemblance between some fruits in the heaven in their qualities and features and the pleasure derived from them, the term "in similitude" has been applied[10].
5- Due to the similarity of all fruits in heaven, "in similitude” has been applied[11].  
 
 

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