Is it permissible for me to make a monthly deduction from my salary as an ongoing charity (Sadaqah Jariyah) for my parents, even though they are financially well-off?

There is no impediment for a Muslim to give charity or dedicate a portion of their salary to charitable works, or perform any good deed and gift its reward to others, whether living or deceased. Scholars have agreed upon the到达 of the reward of charity and supplication to the deceased. The most deserving of those whom a Muslim should strive to benefit are their parents, whether living or deceased, as this is a form of showing them righteousness.