Coral is a marine animal like branches and twigs of trees...
Then which of the Blessings of your Lord will you both [jinn and men] deny? By the word good (ihsan) mentioned herein, doing righteous good deeds and doing good to others are intended.[^2] Imam Sadiq (as) said: "The blessed Verse 'Is there any reward for good other than good' applies to believers and disbelievers, since whoever does good to another, the latter is supposed to return the good done to him." [^3] Imam ‘Ali narrates from the Messenger of Allah (S) that God Almighty said: "Is the reward of the one to whom I have bestowed Favor is other than Paradise?" [^4] In short the blessed Verse in question is saying that those who have done righteous good deeds in this world shall be granted Divine Rewards.
Resuming the discussion the two Gardens in Paradise in store for the God fearing and the enumeration of Divine Blessings, the blessed Verse 62 makes mention of two Gardens in Paradise located on a lower level reserved naturally for those who are on a lower level of belief in and fearing God Almighty. In other words, there is a hierarchy in terms of belief in God Almighty and doing righteous good deeds.
Thus, the blessed Verse in question is saying that two other Gardens are to be found on a level lower than that of the aforementioned Gardens. There are two interpretations for the blessed Verse one of which was already mentioned.
According to the other interpretation, the phrase: "besides these two" (min dunihima) connotes that there are two other Gardens for the same believers who may enjoy themselves in those two Gardens as well, since man seeks diversity by nature and is delighted by the same.