Is it permissible for a Muslim man to ejaculate outside his wife's vagina to prevent pregnancy?

Ejaculating outside the wife's vagina—which is coitus interruptus (al-azl)—is permissible according to the preponderant opinion, provided the wife's permission is obtained. This is because coitus interruptus might deprive her of complete enjoyment or her right to procreate. However, coitus interruptus does not prevent a pregnancy decreed by Allah Almighty, based on the Prophet's (peace and blessings be upon him) saying: "It does not matter if you do not do it, for no soul destined to come into existence until the Day of Resurrection will fail to do so." And his saying: "The Jews have lied; if Allah willed to create it, you would not be able to avert it."