Hagalah and Tevilat Kelim on Silverware From a Non-Jew

The Shulchan Aruch addresses this case directly. For utensils taken from a non-Jew that were used with hot food, one does hagalah first, “and afterwards immerses them” (if they are metal), and then they are permitted. The Rambam gives the same order. The verse says the utensil is passed through fire “and it will become pure,” and the Sages explained that this adds a further purification, immersion, after the kashering through fire.

The Gemara likewise teaches that utensils bought from non-Jews must be kashered according to how they were used. It adds that “all of them require immersion in forty se’ah,” because the verse added another purification beyond the kashering.

• Shulchan Aruch, Yoreh De’ah 121:2 — utensils from a non-Jew used with hot food are first kashered by hagalah and afterwards immersed (if metal)
• Rambam Hilchot Ma’achalot Asurot 17:5 — immersion of eating utensils bought from non-Jews is an added purification after their kashering through fire
• Gemara Avodah Zarah 75b — utensils bought from non-Jews are kashered according to their use, and all of them also require immersion in a mikveh