According to סדר עולם SEDER OLAM, ישראל YISRAʾEL was sprinkled with מי נדה MEI NIDA on 2 Nisan.

ב׳ בניסן ב׳תמ״ט2nd of Nisan, AM 2449

Sinai · W. Asia

https://thisjewish.day/article/2449-01-02-mei-nida-prepared