Are human waste products (sewage), after being thermally treated in factories and converted into fertilizers sold in markets, considered impure? And does using them to fertilize a home garden harm it or make the garden's ground impure and unsuitable for prayer?

The jurists agree on the purity of wine if it transforms into vinegar by itself. However, they differ on the purity of other impurities through transformation (istihalah). The Hanafis, some Malikis, the Dhahiris, and Ibn Taymiyyah are of the opinion that transformation purifies the impure. They argue that the ruling of purity and impurity is linked to the essence of the substance, and if that essence ceases to exist, the ruling is negated. They also argue that the transformation of substances is a greater transformation than that of wine. In contrast, the Shafi'is and the majority of Hanbalis hold that impurity is not purified by transformation. The preponderant opinion is the first one. Accordingly, fertilizers produced from the treatment of impurities are pure, and it is permissible to pray on land that contains them. As for their use in homes, it is up to specialists to ensure there is no harm.