The Enduring Impact of Your Actions: Initiating Good and Evil in Islam
And the person who initiates an evil act will receive the sin for it and also the sin of all those who follow him in this evil act. There will be no decrease in their sin."
For example, a woman gave up all customs in the marriage of her children or a widow got herself married. When other women saw this, they also decided to follow suit.
This woman or this widow who initiated this practice will continue receiving the rewards for this.