Bava Batra 166A

ואימא פריטי! פריטי דדהבא לא עבדי אינשי.

The Talmud asks further: But why not say that the intent is not a dinar, but smaller coins, such as perutot? The Talmud answers: People do not make perutot of gold.

״זהב בדינרין״⁠ – אין פחות מבשני דינרין כסף, זהב. ואימא דהבא פריכא בתרי דינרי דהבא קאמר! אמר אביי: יד בעל השטר על התחתונה.

The Talmud continues its analysis of the baraita, which states: If it is written: Gold, in dinars, the amount must be no less than two silver dinars’ worth of gold. The Talmud asks: But why not say that the document is speaking of two golden dinars’ worth of pieces of gold? Abaye says: This interpretation is also possible, but the guiding principle in all interpretations of ambiguities is that the holder of the document is at a disadvantage.

רישא דקתני: ״כסף בדינרין״⁠ – אין פחות משני דינרין זהב, כסף; אמאי? אימא כספא ⁠– נסכא בתרי דינרי כספא קאמר!

The Talmud asks a question from the first clause of the baraita, which teaches that if the document states: Silver in dinars, the amount must be no less than two golden dinars’ worth of silver. Why is he entitled to so much? Say that the document is speaking of silver only, and means: Two silver dinars’ worth of silver pieces. This interpretation would be a lower value than the interpretation assigned to it by the baraita, and would be in keeping with the principle that the holder of the document is at a disadvantage.

אמר רב אשי: רישא דכתב ״דינרי״, סיפא דכתב ״דינרין״.

Rav Ashi said in reply that the text of the baraita should be emended: In the first clause the case is that the scribe wrote: Silver in dinars, using the plural form dinarei, which refers specifically to golden dinars. In the latter clause, the case is that the scribe wrote: Gold in dinars, using the plural form dinarin, which denotes silver dinars specifically.