Why would a siddur choose תתברֵך instead of תתברַך?

Question

My siddur of choice is the סדור תפילת השלם but I am wondering about one bit of vocalization used therein.

In the davening of shacharit for both weekdays and shabbat, there is a sentence before shma which reads (without nekudot, intentionally)

תתברך...על שבח מעשה ידיך

on Shabbat, the second word is מושיענו while on weekdays, that word is replaced by יקוק אלֺקינו

While in the Artscroll and the siddur Rinat Yisrael, the nekudot under תתברך are the same, with a patach under the reish, in the Tfillat Hashalem, the weekday version reads with a tseirei (titbareich instead of titbarach) and not the patach of the Shabbat davening.

It is the same in all the copies of the siddur that I own and is clearly a choice, not a misimpression of a patach. Is there any any linguistic, grammatical, semantic or other distinction between the two words which would lead to a choice of one in one case, and the other in the other?

Answer 1

In truth, it's a very old מחלקת. It's mainly about the words יתגדל ויתקדש. Some מדקדקים thought that, even though we find both pata'h and tsérei occurrences for that type of word in the Torah, the normal one is with a tsérei, but in all old nuscha'os including rishonim, it's with a patach. This argument is brought by the סידור רב שלמה סופר מפרמישלה, whose נוסח is the basis of נ׳ אשכנז since the XVIIth century. But the GR"A, even if he doesn't discuss the דקדוק part of the subject, felt that it should be said in that particular instance (Kaddish) with a tsérei because it follows the wording of a פסוק in (יחזקאל (לח כג where it is with a chirik, which corresponds to tsèrei. A lot of poskim understood that the GR"A disagreed with RaSHa"S and that's how the old מחלקת resurfaced.

Answer 2

extract from siddur sefas yisroel: