From Sahih Bukhari (Hadith 1414):
Narrated Abu Musa:The Prophet (ﷺ) said, "A time will come upon the people when a person will wander about with gold as Zakat and will not find anybody to accept it, and one man will be seen followed by forty women to be their guardian because of scarcity of men and great number of women
Reference: Bukhari 1414