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

73. It is a negative commandment “do not make a decision on the statement of one witness.”

As it states in Devarim (Deuteronomy) 19:15, “a single witness shall not stand up against a man regarding any sin or transgression.” This means, a person is not punished by a statement made by only one witness.

This applies in all places and at all times.