A vow of sacrificing an animal at a specific time and distributing it to the poor

Question 14: If I made a vow to offer a sacrifice in the month of Muharram, Safar, or any other month; is it permissible for me to pay the value of the sacrifice to the needy or do I have to offer the sacrifice and distribute its meat to the needy? Please enlighten us!

Answer: Anyone who makes a vow to offer a sacrifice during a specific time and distribute it to the needy has to fulfill their vow at the specified time. The Prophet (peace be upon him) said: Anyone who vows to obey Allaah should obey Him (i.e., fulfill their vow). It will not be sufficient to pay the value of the sacrifice they vowed to offer to the poor... read more here.

Acts of Jaahiliyyah (age of ignorance) in Muharram

Question 13: During the month of Muharram, women go to the house of a newly married woman and bring water with them. They wear thick clothes to protect themselves against the cold and splash some of that water over the newly married woman and pour the rest over themselves, including young and old women. They do this every year. When we ask them to give up this action, they say that it is part of their habits and traditions.

Answer: This habit is an invented practice from Jaahiliyyah (pre-Islaamic time of ignorance) and it is not permissible for a Muslim to do it since it does not have any origin in Allaah’s Purified Shar‘ (Law)... read more here.