Is it permissible to donate cold water every Friday to construction workers—who may not be Muslims—with the intention of it being an ongoing charity (sadaqah jariyah) on behalf of the deceased?

Charity through providing water is the best form of charity. Giving charity on behalf of the deceased is permissible, and it can be given on behalf of both Muslims and non-Muslims. However, dedicating Friday specifically for charity is a matter of scholarly disagreement. Some, like Al-Shatibi, considered it an innovation, and the Permanent Committee concurred with them. Others, however, believe that good deeds are multiplied due to the honor of the time and place, such as Friday. This view was favored by Ibn Rajab, Al-Bahuti, Ibn Baz, and Ibn Hajar. It was narrated from Ka'b Al-Ahbar that charity, good deeds, and bad deeds are multiplied on Friday, while a weak hadith from Ibn Abbas speaks of the virtue of giving charity on Friday.