What is the opinion of Shaykh al-Islam Ibn Taymiyyah concerning the purity of fish blood?

The Hanbalis differed regarding the purity of fish blood, and the relied-upon opinion in the madhhab (school of thought) is that it is pure. Shaykh al-Islam agreed with this, arguing that all blood is impure except for the blood of edible animals, such as the liver and spleen, what remains on the meat after slaughter, and fish blood. This is because fish blood is pure; if it were impure, it would be obligatory to drain it through tadhkiyah (slaughtering according to Islamic rites).