What is the ruling on leaving pubic hair unshaven?

Shaving the pubic hair is among the practices of fitra (innate disposition) that Prophet Muhammad, peace and blessings be upon him, encouraged. Al-Bukhari narrated from Ibn 'Umar, may Allah be pleased with them both, that the Messenger of Allah, peace and blessings be upon him, said: "Five things are from the fitra: shaving the pubic hair, clipping the nails, and trimming the mustache." Shaving the pubic hair is called istihdad because it involves using an iron blade. It is a sunnah (definition) (prophetic tradition) and its purpose is to cleanse the area.

The Prophet, peace and blessings be upon him, specified that these matters should not be left for more than forty nights, as narrated by Muslim from Anas, may Allah be pleased with him. Al-Nawawi was of the view that the meaning is that they should not be neglected to the extent that they exceed forty, i.e., the period should not exceed 40 days, while it is recommended for a Muslim to attend to this from one Friday to the next.