Musannaf Ibn Abi Shaybah

Hazrat Abu Yahya, may Allah have mercy on him, narrates that a man asked Hazrat Abdullah bin Abbas, may Allah be pleased with them, "O Ibn Abbas, may Allah be pleased with them! I take my private part in my hand and I ejaculate; what is the ruling on this?" Hazrat Ibn Abbas, may Allah be pleased with them, replied, "Uff, uff! This is not like adultery, but it is better for you to marry slave women than to do this."

Hazrat Ibn Abbas (may Allah be pleased with both of them) said that the one who masturbates is committing fornication with himself.

Hazrat Ibn Umar (may Allah be pleased with both of them) was asked about masturbation, so he replied that he is one who commits fornication with himself.

Hazrat Qasim (may Allah have mercy on him) was asked about this verse of the Holy Qur'an: "Those who guard their private parts, except from their slave women and wives, they do not fulfill their desires elsewhere; in this matter, they are not to be blamed. But those who go beyond this limit, they are the transgressors." Upon this, Hazrat Qasim (may Allah have mercy on him) said that those who fulfill their desires elsewhere than with their slave women and wives are the transgressors.