To what extent is the narration sound regarding Khalid ibn al-Walid anointing himself with wine, as transmitted by Ibn Asakir, and is it established and authentic to be used as evidence, especially since it has not been cited by those who maintain the impurity of wine?

This narration is neither sound nor does its chain of transmission authenticate it. Even if we assume its authenticity, it does not indicate that Khalid ibn al-Walid considered wine to be pure. Rather, it contains what indicates that he considered it impure. For he did not respond to Umar by saying that wine is not impure. Instead, he responded by saying, "We have killed it, so it has become a washing agent, not wine." This means that it has undergone transformation, fermented, and lost its intoxicating quality, thus it is no longer wine. He also clarified in some of his verses that it no longer resembles wine in taste, flavor, and intensity. Generally, the vast majority of scholars consider wine to be physically impure.