January 17

The most important thing is to polish the mirrors of hearts in order that they may become illumined and receptive of the divine light. 
(‘Abdu’l-Baha, from a talk, New York, 14 April 1912; ‘The Promulgation of Universal Peace: Talks Delivered by 'Abdu'l-Bahá during His Visit to the United States and Canada in 1912’)