תלמוד על פרה 12:5

“Ink.” If one carried out ink in a reed pen, sufficient to write two letters. If it was in a vessel it needs more⁹⁰Since to fill the pen one needs more of the ink. The Babli disagrees, 80a.. There, we have stated⁹¹Mishnah Parah 12:5. The minimum amount is what is needed to dip the heads of two stalks of hyssop. In a vessel this might require a larger amount. Cf. Note 82.: “How much water is needed for one sprinkling? Rebbi Jeremiah asked, would it not be reasonable that in a vessel it would need more?