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
First Section – the Positive Commandments
11. It is a positive commandment to say Shema in the morning and evening.
As it says in Devarim (Deuteronomy 6:7), "And you should speak in them when you lay down to sleep and when you wake up." And this means the time that you lay down and the time when you wake up. Shema is three paragraphs: Shema (Devarim 6:4-9), Vehaya Im Shamoa (Devarim 11:13-21), and Vayomer (Bamidbar 15:37-41). The first paragraph, Shema, contains the Oneness of His name and loving Him, may His name be blessed; learning Torah; and that He the peg that all things depend upon. The second paragraph, Vehaya Im Shamoa, has in it accepting the yoke of the other commandments. The third paragraph, Vayomer, is the paragraph about tzitzis and tzitzis is a remembrance of all of the other commandments. It also has the commandment to remember the exodus from Egypt as it says in Devarim (Deuteronomy) 16:3, "In order that you remember the day you left the land of Egypt all of the days of your life.”
And this is obligatory in all places and at all times, for men but not for women.