||There are two halves to this page. The top consists of four "headlines”: 1) the importance and seriousness of the family purity laws, 2) the importance of using a kosher Mikvah in the performance of Tevila, 3) the Talmudical statement that a community should provide a Mikva before any other public institution and 4) that each member of the community should help maintain a center for family purity. This is signed by eight prestigious Rabbis, including R. Yitzhak Halevi Herzog, R. Tzvi Pesach Frank, R. Ya’akov Moshe Charlop, and others.
The bottom half of the page is headlined with the phrase Kedoshim Tehiyu - that the obligation of the Jewish people is to be holy "because I (meaning Hashem) am Holy".
Incorporated into this general dictum is the very conception of a child that requires adherence to family purity laws (which requires building kosher mikvaot). "And what should we answer? We should all decide, as one man, to do and see that it is done. To act, to donate and to see that others donate."
This is signed by the Hasidic Grand Rabbis, such as the Admor of Gur R. Abraham Mordecai Alter, the Admor of Belz and 15 others. The Belzer rebbe arrived in Erez Israel at the conclusion of their dramatic escape from Nazi occupied Europe in 1944. The Gerrer Rebbe died during the war for independence in 1948, so it would seem that this poster was published between 1944 and 1948.