13A, the gemarah discusses why the parshiyos of krias shema are in a specific order.
The second is before the third, because the 2nd has mitzvos by day and night while the 3rd is only night.
Now I understand that it is going on the mitzva of tzizis. However there are other comandments in the 3rd that are also by night. Lo sosuru, yetzas mitzrayin, ani hashem?
Gemara on 14b says that Yetzias Mitzrayim can be recited some other way.
With regards to the other Mitzvos listed on 12b, עול מצות ודעת מינים והרהור עבירה והרהור עבודה זרה, those ultimately all branch out from the מצוה of ציצית, the פשוטו של מקרא is that by looking at ציצית, it will lead on to the other aspects involving עול מצות ודעת מינים והרהור עבירה והרהור עבודה זרה. At night, when it is not זמן ציצית, then you don't have the
זכרון for these other aspects as well.