פירוש על עבודה זרה 150:12

R. Nahman says that even new vessels, those never used and therefore that have not absorbed the taste of any prohibited food, must be immersed. He derives this from the fact that immersion is required even if the vessels were first kashered by fire (which is mentioned in the biblical passage). Such cleansing will utterly rid the vessel of any taste and make it like new. Nevertheless, it must be immersed. From here we can conclude that all vessels bought from non-Jews must be immersed.

If even vessels that have no residue of taste in them must be immersed, then why not say that even scissors need to be immersed? R. Nahman answered that the only types of vessels mentioned in the biblical passage are those used in connection with meals. Shearing scissors are not included.