Is it permissible for a married man who is a sojourner in a land of temptations to masturbate to quench his desires?

Masturbation is forbidden (haram (definition)). The presence of desire (shahwa) can only be treated by marriage, or by fasting for those who cannot marry. A Muslim must strive against their own soul (nafs) by refraining from looking at forbidden things, and by occupying themselves with righteous deeds such as remembrance of Allah (dhikr), reading the Qur'an, and prayer. They should also engage in physical activities, associate with good companions, and avoid being alone.