What is the ruling on selling temporary breast and lip augmentation devices, hair styling devices, and cosmetics and skin and hair care products to women who do not wear hijab or niqab? Is this considered altering Allah's creation? Is it permissible to benefit from external-use products that contain snake or viper oil?

It is permissible to sell goods that can be used for both lawful and unlawful purposes, unless it is known that the buyer will use them for an unlawful purpose, such as cosmetics for someone who will use them for ostentatious display (tabarruj). As for devices for lip or breast augmentation, they do not fall under the prohibited alteration of God's creation.

Regarding the external use of snake or viper oil, it depends on its purity or impurity. The majority of scholars hold that snakes are among the impure (khaba'ith) and are not edible, so their fat is impure (najis). It is not permissible to use it except for medicinal purposes out of necessity. Scholars have differed on the permissibility of selling it or benefiting from it.

Imam Al-Shafi'i held that it is permissible to treat with it externally if it is pure and safe. On the other hand, Ibn Qudamah held that it is not permissible to treat with it if it is impure. Some scholars permitted using impure oil for lighting, provided its impurity does not spread. Al-Haytami held that snake venom is impure. Others held that snake skin does not become pure by tanning. The preponderant view is that snake oil and fat are impure, and it is not permissible to anoint oneself with them except in cases of extreme necessity if no alternative is available.