Responsa zu Kilayim 9:11

I also asked [in my dream] regarding woolen garments purchased from non-Jews. Is it necessary to be concerned that they might be sewn together with linen threads¹This seems to be the opinion of Rabbeinu Tam in Tosafot on Yevamot 5b:5, or do we say that sewing linen is only a rabbinical prohibition, and therefore in any case of doubt we should be lenient?²This is the opinion of Rashi on Yevamot 5b:5, and of his son-in-law Rivan (see Tosafot ad loc.) Together with this question, I also asked [in my dream] regarding leather which is known to be sewn with linen threads, and which is then attached to woolen robes. I asked whether there is a prohibition to attach them to wool once they are sewn with linen³This is possibly the opinion of Maimonides in Mishneh Torah, Kilayim 10:3. R. Hezekiya (possibly Hezekiya ben David, a contemporary of Hai Gaon) is reported to have been stringent with such leather (Terumat Hadeshen 297), or whether it is permitted⁴This is the opinion of R. Samson of Sens (Rash Mishantz on Kilayim 9:9).