Negative Commandment #193
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
193. It is a negative commandment "an impure person may not enter the Camp of Levi, which is the Temple Mount"
As it states in Devarim (Deuteronomy) 23:11, "If there is among you a man who is not ritually pure... do not come within the camp." Our Sages of blessed memory received the tradition (Gemara Tractate Pesachim 68a) that this means the Camp of Levi, which is the Temple Mount. A ritually impure person who does not obey this and enters the Temple Mount has transgressed this negative commandment.
This applies even nowadays, for men and for women, since we are ritually impure from coming in contact with the dead.