467. Tzitzis at Night

Tzitzis 3:7

Techeiles (which is wool) should not be attached to a linen garment; one should only make the white strings of linen. This is not because shaatnez trumps tzitzis but because it is a rabbinical law instituted out of the concern that one might wear this garment at night, when a person is not obligated in the mitzvah of tzitzis. If one were to wear this garment at night, when the mitzvah of tzitzis does not apply, he would be in violation of shaatnez. We derive that one is only obligated to wear tzitzis by day from Numbers 15:39, “you shall see them” – i.e., at a time when one can see them. Despite this, a blind man is required to wear tzitzis; even though he will not see them, others will.

Tzitzis 3:8

One may wear tzitzis at night, both on weekdays and Shabbos, even though it is not a time when the mitzvah is fulfilled; one does not recite a bracha. The bracha on tzitzis is recited in the morning when the sun has risen sufficiently for one to be able to differentiate between the white strings and the techeiles. The bracha recited is that God “has sanctified us with His commandments and commanded us to wrap ourselves with tzitzis.” A person should recite the bracha every time he wraps himself in tzitzis by day. No bracha is recited when making tzitzis because the ultimate goal of the mitzvah is to wear them.