Question: [Sunday, 29th Nissan, 5781]
If I don’t change my Tzitzis in the morning, am I still obligated to check them daily? I currently have only one pair which I don’t change or take off and sleep with at night, and therefore my question.
One is obligated to check his Tzitzis daily prior to putting them on. This applies even [and perhaps especially] if one slept with them and momentarily took them off in the morning such as to change his undershirt, or upon going to mikvah. However, prior to taking them off and re-wearing them, there is no obligation to check them. Nonetheless, regardless of the above, one is still obligated to separate the strings from entanglement in order so they are loose and separated.
Explanation: The sages established that one must check his Tzitzis each morning prior to wearing it in order to prevent saying a blessing in vain and wearing an invalid pair of Tzitzis. This obligation however only applies prior to putting it on, and therefore one who is not putting it on being that he slept with his Tzitzis and did not take it off, then he is not obligated to check it. The reason for this is because the Takana was to check the Tzitzis each day upon wearing it in order to prevent a situation that one will never check the Tzitzis. However, if one is already wearing the Tzitzis there is no need to check the Tzitzis [even if one did not yet do so that day] being that he will re-check it when he removes it and wears it the next time.
Sources: see regarding the obligation to check daily: Admur 8:13; Siddur Admur; Michaber 8:9; Rosh end of Hilchos Tzitzis; see regarding if one did not remove: Tehila Ledavid 8:4; see regarding the obligation to separate the strands daily: Admur 8:12; Siddur Admur; Michaber 8:7; Menachos 42a