Checking Threads in Advance of Use

W-ith H-shem's help, we have begun learning Hilchot Tzitzit with the Ben Ish Chai, Hacham Yosef Hayyim of Baghdad. The sefer is translated by Shmuel Hiley and published by Yeshivath Ahavath Shalom Publications in Jerusalem 5765/2005. He calls the names of the Chapters by the names of Parashiot, so instead of Chapter One, the first chapter is called Parashath Bereshith, Laws of Ziziyoth. Please note these are for learning purposes only.  For the halacha lemaaseh, i.e. for what to do yourself please ask your own Rav.  So let's begin:

Parashath Bereshith, Laws of Ziziyoth, Page 2-3
3. Before reciting the berachah over the tallith, one should examine the threads of the ziziyoth to ensure that there is nothing wrong with them that would render them pasul.  One should also untangle the individual threads of the ziziyoth (this may not be done on Shabbath, but one should still examine them for any possible defect).  It is the hole in the corner of the tallith, because if even one thread is severed at that point, the entire zizith becomes pasul.

If there is not enough time to examine the threads, for example if one happens to arrive late at the synagogue {and finds that the congregation has already begun prayers, and one has to hurry to catch up}, or if one has been honoured with opening the hechal, or reading from the Torah {and any delay would inconvenience the congregation}, it is permissible to rely on the halachic principle known as hazaqah, and not examine them.

Likewise, the Posqim HaAharonim write that one may rely on this principle (and not inspect the zizith before use) when travelling since, should the zizith be found to have become pasul and a replacement tallith is unobtainable, one would be forced to forego the mizwah altogether.

This learning should be in memory of Maran, HaRav HaGaon Ovadia Yosef, ztz'l.