Can someone help me to understand the grammatical/ interpretive point that the Malbim is making in his commentary to Leviticus 6:21 (the entries numbered 67 and 68 on Sefaria)?
In 67 he is making the point that when someone mentions the parts comprising a category, it would not do to leave out any parts of the category. But sometimes the individual parts can be grouped into mini-categories that contain all the parts. For example, all colors could be grouped under darks or lights, as we do with laundry. So too in the passuk, bronze includes all metals which are similar to bronze, and pottery includes all similar materials.
However, this only applies when you can see that the Torah is using categories. In a case where the Torah just says use a certain material, you have to assume it means that material specifically.