Does the inward impurity of a dog disappear if it is removed by the sun, wind, or similar means? Is it necessary to purify it seven times, the first of which is with earth, in this case? What is the fiqh (understanding) of the hadith mentioned in this regard, and what is the scholarly disagreement surrounding it?

Scholars differ on the purification of an impure land. The Hanafis, one narration from Ahmad, and the view chosen by Shaykh al-Islam, hold that it is purified by the sun, wind, and dryness. The Shafi'is and the relied-upon view of the Hanbalis hold that it is not purified except by pouring abundant water over it. They also differed regarding the impurity of a dog if it touches the ground. The Shafi'is hold that washing seven times is obligatory (without soil), while the Hanbalis deem pouring abundant water sufficient. The more cautious approach is to act according to the madhhab of the Shafi'is.