ציטירנדיקער פּירוש אויף ירמיהו 32:11

"Because it needed to teach 'money'". And here it is not fitting to object "But he taught two as one!" as [the Talmud] objects later [regarding sex], for the terminology of "acquisition" is fitting also for contract and sex. And one should not be surprised about the terminology of "acquisition", rather because later it taught with the terminology of kiddushin and here it taught with the terminology of acquisition. Alternatively: With a contract we also find the terminology of acquisition, as it is written, "I took the book of acquisition" (Jeremiah 32:11).