Negative Commandment #20
Sefer Ha’mitzvos Ha’Katzar (The concise book of mitzvos)
By the Chofetz Chaim
This book lists the Torah mitzvos that can be observed today
Second Section – the Negative Commandments
20. It is a negative commandment not to have mercy on idol worshippers
As it states in Devarim (Deuteronomy) 7:2, "Do not have mercy on them." If a person sees an idol worshipper drowning, he should not save him. If the idol worshipper is sick, he should not heal him. If he is afraid of the idol worshipper, or if it will cause hatred against the Jews, the Jewish person can heal him for payment, but not for free. It is forbidden to kill him with your hands or to push him into a pit or any similar actions, unless the idol worshipper attacked first. A Jew may not give him a gift for free, nor praise him or his actions.
This applies in all places and at all times, for men and for women.