Nizar Rayan (Arabic: نزار ريان‎, Nɩzár Rɑȋán; also transliterated Rayyan) (6 March 1959–1 January 2009) was a top Hamas leader who served as a liaison between the Palestinian organization's political leadership and its military wing. Also a professor of Islamic law, he became a top clerical authority within Hamas after the death of Sheikh Ahmed Yassin in 2004. Rayan was a strong advocate between 1994 and 2004 or 2005 of suicide attacks on Israel, and his son killed himself on one such mission.