Question 125: Is the semen from which man is created pure or not? If it is not impure what is the wisdom behind Ghusl (ritual bath following major ritual impurity)? Is it prohibited to delay Ghusl until the morning in winter for fear of the cold weather?
Answer: All praise be to Allaah Alone, and peace and blessings be upon His Messenger, and his family and Companions. The sound opinion is that semen is pure. When it is ejaculated in spurts from a person lustfully through sexual intercourse or a wet dream, Ghusl is compulsory. It is permissible to delay it until morning. A person should take Ghusl to offer Fajr (Dawn) Prayer in its due time. It is not permissible to delay it until the prayer due time is over… read more here.