Ocean of pearls and corals denote the Imams (a.s.)
Allah the most high says in Surah Rahman:
مَرَجَ الْبَحْرَيْنِ يَلْتَقِيَانِ. بَيْنَهُمَا بَرْزَخٌ لَا يَبْغِيَانِ. فَبِأَيِّ آلَاءِ رَبِّكُمَا تُكَذِّبَانِ. يَخْرُجُ مِنْهُمَا اللُّؤْلُؤُ وَالْمَرْجَانُ.
He has made the two seas to flow freely (so that) they meet together: Between them is a barrier which they cannot pass. Which then of the bounties of your Lord will you deny? There come forth from them pearls (lolo) and corals (marjan). (Surah Rahman 55:19-22)
Most commentators say that two seas denote a salty one and a sweet one. The sweet water enters the salty sea and by the power of Allah they mix together and pearls come into existence where these waters mix together. Some have said that it refers to the sea of the sky and the sea of land and when the rain-bearing cloud rains on the sea the shells open their mouth and pearls are made from it. Others have said that it refers to the sea of Persia and the sea of Rome. In the explanation of these verses many traditions has been narrated from the Ahle Sunnat and Shias.
Thalabi from Ahle Sunnat has narrated from Sufyan Thawri and Ibne Jabir that the two seas are Ali and Fatima (s.a.) and the Holy Prophet (S) is the ‘barrier’ and ‘pearls’ and ‘corals’ are Hasan and Husain (a.s.). The big pearl refers to Imam Hasan and Husain is compared to a small pearl or with coral, whose redness is associated with the martyrdom of Imam Husain (a.s.).
Shaykh Tabarsi has narrated from Salman Farsi, Saeed Ibne Jubair and Sufyan, and Ibne Mahyar has also narrated this from Ibne Abbas and also from Ahle Sunnat sources it is narrated from Abu Saeed Khudri and from Shia chains from Imam Ja’far as-Sadiq (a.s.) that the two seas are Ali (a.s.) and Fatima (s.a.). It means that neither Ali does injustice on Fatima nor Fatima does injustice on Ali and Hasan and Husain were born from them.1
Ibne Mahyar has narrated through Sunni chains from Abu Zar that the two seas are Ali and Fatima (s.a.) and ‘pearls’ and ‘corals’ are Hasan and Husain (a.s.). And who has seen anyone like these four. Only the believer befriends them and only the unbeliever hates them. So remain a believer due to the love of Ahlul Bayt (a.s.) and do not become an unbeliever by hating them, otherwise Allah cast you into Hell.
Ibne Babawayh in Khisal has narrated from Imam Sadiq (a.s.) on this verse that Ali and Fatima (s.a.) are the two deep seas of knowledge, none of whom does injustice on the other; and pearls and corals are Hasan and Husain.
Ibne Shahr Aashob has narrated from Ibne Abbas that one day Fatima (s.a.) complained to the Holy Prophet (S) about her poverty and difficulties. The Prophet (S) said: O Fatima! Be content with your husband because he is a Sayyid and a leader and he is the best of all the creatures in this world and the hereafter. At that time Allah revealed this verse:
He has made the two seas to flow freely…
Ali Ibne Abi Talib is the sea of knowledge and Fatima is the sea of Prophethood who are connected to each other and I have connected them. It means that there is a barrier between them which is the personality of the Prophet (S), who refrains Ali from becoming sad in the world due to poverty and refrains Fatima from saying anything against Ali.
So, O the nations of people and Jinn, which of the bounty of Allah—it means the Wilayat of Ali (a.s.) or the love of Fatima (s.a.)–would you deny? Because these two are the great blessings of Allah for you, that is why ‘pearl’ means Imam Hasan and ‘coral’ means Imam Husain (a.s.) because ‘lolo’ is big pearl and ‘marjan’ is the small pearl.