Reference for Gittin 34:13

אמר ליה רבינא לרבא כתביה

For if you say this is of no value, [I might retort,] even when the day is specified, do we know whether the morning or the evening is meant? What [it does is] to distinguish it from the day before and the day after. So here, [by specifying the septennate] we are enabled to distinguish it from the septennate before and the septennate after [should a question arise about them]. Rabina said to Raba: If a man writes a Get

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