I say, and with God's success: It is purified by washing it seven times with dirt as a recommendation, and by washing it three times, one of which must be with dirt as an obligation; based on the hadith of Abu Huraira (may Allah be pleased with him): The Messenger of Allah (peace be upon him) said: "The purification of the vessel of any one of you when a dog licks it is to wash it seven times, the first of which is with dirt," in Sahih Muslim 1: 234, and Sahih Bukhari 1: 75, and it is understood as a recommendation. This is because it was narrated that the Messenger of Allah (peace be upon him) was asked about a dog licking from a vessel, and he said: "Wash it three times or five times or seven times," and from Abu Huraira (may Allah be pleased with him) he said: "It is washed three times when it licks it," in Sharh Ma'ani Al-Athar 1: 22. Thus, Abu Huraira (may Allah be pleased with him) acted contrary to what he narrated, as he washed it three times, which confirms the abrogation of the seven times; for we have good thoughts about him, and we do not assume that he would neglect what he heard except in a similar manner, and Allah knows best.