According to Sa’id bin ‘Abdullah once he asked some questions to Imam al-Mahdi when he was very young and was sitting on a lap of his father Imam Al-Hasan ‘Askari Sa’id bin ‘Abdullah asked Imam to explain the meaning of “Kaf-Ha-ya-Ain-Suad.” Imam at once said that there is a great secret behind of these letters. Allah has given the knowledge of these letters to Zakariyya and the last Prophet, Muhammad al-Mustafa.
It is said that Zakariyya requested the Almighty to make him know the names of the people of the cloak. By the order of Allah Archangel Gabriel approached him and taught him the names of the people of the cloak. When Zakariyya was reciting the names of Muhammad, ‘Ali, Fatimah, hasan his tension and sadness dissipated at once but when he recited the name of husayn, his throat was choked and he started crying. Then one day after reciting Dua and prayer he asked Allah the reason of his crying by reciting the name husayn.
Allah, the beneficent told him about the incident of Karbala by revelation: ‘Kaf’ means Karbala, ‘Ha’ means the martyrdom of the son of Rasul Ya’ means Yazid, ‘Ain’ means thirst and hunger of the family of husayn. ‘Suad’ means Patience of Imam al-Husayn.
When Zakariyya heard this, he felt, too much sorrow. He could not come out from his place of worship and forbade people to come and see him. He was saddened deeply, prayed to Allah by crying at Imam’s martyrdom. He said, “O, Allah! You will test your Prophet Muhammad al-Mustafa’s heart by grievances and troubles for the people of world to spread the principles and laws of Islam! Imam ‘Ali and Fatimah will also mourn and wear black dress for Imam al-Husayn’s martyrdom!”
He prayed, “My Lord! Grant me a son, I will prove myself as a truthful servant. O Allah make me cry and sad for my son’s troubles and sorrow as you will make your Prophet sorrowful for his son Imam al-Husayn’s grief.”
Allah the Merciful granted him a son named Yahya. His mother’s pregnancy was only of six months and Imam al-Husayn’s was also the same.