Seeing oneself write beautiful script signifies working for the righteousness of religion and worldly life.
Seeing someone write something for oneself signifies goodness, benefit, and attaining one's wish. Writing on a sheet of paper signifies inheritance.
Seeing a verse from the Qur'an written on one's shirt signifies following the Qur'an, obeying its rulings, and righteousness in religion. Writing with the left hand signifies ugly and evil deeds and error.
Abu Sa'id al-Wa'iz said: Writing on paper signifies denying a right. Writing with blood signifies drawing up a deed or document for usurious wealth.
Ibn Sirin said: Seeing oneself write a book signifies the possession of unlawful wealth, in reference to the Qur'anic verse meaning, 'Woe to those who write the Book with their own hands and then say, 'This is from Allah,' in order to exchange it for a small price' (al-Baqarah 2:79).
Seeing one's own writing as bad signifies repentance from sins.
Seeing oneself write a book but fail to complete it signifies that the dreamer's affair and need will be completed.