Zayn al-Abidin had seven wives by which he had 11 sons and 4 daughters. His first wife was Fatima bint Hasan bin Ali, who gave birth of Muhammad al-Bakir. His other sons were Abdullah, Zaid, Umar, Hasan, Hussain Akbar, Hussain Asghar, Abdur Rahman, Suleman, Ali Jawad and Asghar. His daughters were Khadija, Fatima, Umm Kulsum and Aliya.
His collection of prayers is known as "Sahifa-i Kamilah" (the book of perfection), or also called "Sahifa al-Sajjadiyya" (the scroll of Sajjad). Its collection was made by his sons, Muhammad al-Bakir and Zaid. Out of 75 prayers, 11 were lost and 8 are considered as apothyphal owing to anachronisms. In its present form, now consists of 71 prayers, and have been designed on the pattern of the Pslams of David containing 150 songs, and therefore, it is also named as "Psalms of Ahl-al-Bait."The prayers of "Sahifa" also contains the notion of astronomy, the cosmos, the secrets of navigations etc. Examining the 43rd prayer, which the Imam had invocated while looking at the new moon, we will find the theory of "rotation of moon", which reads as under:-
Once an astrologer went to Zayn al-Abidin, when Imam told him: "I shall introduce you to a person whose journey, during the interval taken by you in coming to me, has extended to fourteen universes, of which each universe is three times as bigger as our earth, and all this has happened in spite of the fact that the person has not moved from his place." The astronomer thereupon asked: "Who is this personage?" Imam replied: "It is I. If you wish I can tell you what you ate today at home, and what lies in your house." In this tradition, however, those universes are referred to, every one of which is bigger than our earth, that is, of course nothing but our Solar System.