וְאָסַ֣ף ׀ אִ֣ישׁ טָה֗וֹר אֵ֚ת אֵ֣פֶר הַפָּרָ֔ה וְהִנִּ֛יחַ מִח֥וּץ לַֽמַּחֲנֶ֖ה בְּמָק֣וֹם טָה֑וֹר וְ֠הָיְתָה לַעֲדַ֨ת בְּנֵֽי־יִשְׂרָאֵ֧ל לְמִשְׁמֶ֛רֶת לְמֵ֥י נִדָּ֖ה חַטָּ֥את הִֽוא׃
А чистый человек соберет прах телицы и положит их без стана в чистом месте, и он будет храниться для общества сынов Израилевых, для воды окропления; это очищение от греха.
On Dreams
§ 214. Ashes. As the point is essential to Philo’s illustration, one must suppose that he found, or thought he had found, some authority for the statement that ashes were used in purificatory ritual. The nearest evidence I can find is the use of the “ashes of the heifer” in Num. 19:9, alluded to in Hebrews 9:13. Possibly τέφρα, like κονία, may have been a name for some kind of lye or soap, but I know of no evidence for it.