What is SA Harav's opinion about parshiyos that descend from the batim into the area of the titura?
SA Harav 32:55: Totafos mentioned in the Tora chachamim received [the explanation] as 4 [batim] pockets of leather for 4 parshiyos, each parsha in a [special] pocket by itself…
"each parsha in a [special] pocket by itself " – each parsha has a designated area - its private bayis. If it isn't in its bayis, it is pasul [from the Tora – this is not totafos].
SA Harav 32:61: The charitz [crack separating] between the batim must descend till the tfira, if not it is [still] kosher, if it [the charitz] is at least recognized at the top of the bayis…
When is this so, when inner separations [mechitzos] were made [added-glued] between the pockets [batim] from the top till the end of the width of the parsha … but if he did not do so [these inner separations] or the leather between each parsha and parsha was torn it is pasul…
SAH is clearly teaching – any parsha that isn't totally in its private bayis, is not kosher. This includes 2 laws:
a. if the parsha descends out from its bayis, it is pasul.
b. if the mechitzos are not complete between the batim totally separating one parsha from another, it is pasul.
SA Harav 32:77 is relating to the tfira (sowing) of the bayis – it must be sown into the titura [Today batim mehudaros are made totally from one piece "miksha" the batim and the titura are all one piece, and they are molded into shape. This is an invention started in Yerushalayim 100 years ago, beforehand all Tefilin were made - the bayis a separate piece and the titura a separate piece – the upper titura was cut in the middle as a window to allow the bayis through, and they were sown together the bayis into the 2 folds of the titura. The SAH is relating to this type]:
The tfira has to be sown through folds [flaps] of leather extending from the bayis, so that the bayis is sown … and if not is pasul, since the hallacha l'moshe m'sinai mentions "tefilin must be sown", the batim are [the] tefilin, and not the titura, therefore the square [ribua] must be also in the batim and the ribua of the titura is not enough [alone] because they [the gemara] said "square Tefilin hallacha l'moshe m'sinai" and the batim are named tefilin, but the titura is named [only] 'titura of tefilin'.
The SAH is teaching that the titura is not iykar ha'tfilin – the main element, they are an accessory only. When tefilin are mentioned in hallacha l'moshe m'sinai, it relates to the batim.
From this it is pashut that if the parshiyos descend into the titura, which is not called bayis, they are out of place and pasul.
But what about the batim that are 'miksha' one piece the titura and bayis, can the parshiyos descend into the area of the upper titura? Maybe since the leather is one piece, the upper part of what is called titura is in reality part of the bayis itself?
The same question applies to the batim miksha that the mechitzos inside the shel-rosh descend all-the-way down [through the upper titura] till the bottom of the upper titura. Are these extensions [mechitzos yordos] in shel rosh, considered the batim shel rosh so the parshiyos can descend into them, or not? [But shel rosh that don’t have these mechitzos yordos all the way down and the mechitzos finish at the end of the bayis (like the old gasos), it's pashut that if the parshiyos descend out of their pocket, is pasul as explained above].
The basic question: What is the status of what is called today [in gasos] 'the upper titura' - if it is indeed a titura it should be pasul to allow the parshiyos in them, but if this part is only called 'upper titura' by name, but actualy can be considered the bayis, it may be kosher to allow parshiyos descending there.
The question is: Is there a true need for an 'upper titura' m'doraysa, or maybe the true titura is only the bottom part that sows the tfilin closed – that is "titura shel tfilin hallacha l'moshe m'sinai". The top part in the old tefilin was only to allow the sowing of the batim to be secure in place [the old tefilin were made out of dakos, and sowing the flaps of the bayis from dakos by themself into the titura wouldn’t hold long].
If so - today tfilin gasos have no need for a upper titura, maybe it is actualy the flaps of the bayis itself, and not a titura.
From the SAH 32:66 explaining what titura is – a piece to cover the opening of the batim underneath - it seems that the titura is the lower piece, not the top one.
If so why are we makpid to square the top titura, see MB 32:177, and in Sha'ar Hatziyun he doubts if this is me'akev (it seems that his doubt is as above, what is the true status of the upper titura. See also Minhas Yitzhak vol. 6:1).
So if it is a safek, according SAH it should be forbidden as safek de'oraysa!
Another problem is, let's say it isn't the titura but an extension of the bayis – the square isn't the same square measure as the bayis is!
Although squared itself, the titura is wider than the bayis. The simple pshat in SAH 32:59 "the bayis has to be square its total hight" means the same square, it doesn’t make sense that he would mean that the bottom part of the bayis can be square 4X4 the top 5X5, rather the bayis has to have the same squre from top down. Since the titura is squared different – the parshiyos can not be there, because it is not in the square part of the bayis (which is Hallacha l'moshe m'sinai)!
I think the last reason alone is sufficient to forbid parshiyos in the upper titura in any [gasos] tefilin!!
I think that SA Harav 32:61 The charitz [crack separating] between the batim must descend till the tfira … also indicates the boundary of the bayis. The charitz should descend till the end of the bayis, that is the tfira. Now it is obvious he means the upper side of the tfira, because the charitz once inside the upper titura is not seen, so what is the use of a charitz [in miksha] descending lower. It is more logical that this creates a definition - where the bayis ends. [From shel rosh I think the same in shel yad, although it doesn’t have a charitz, the boundary of the bayis is the upper tfira].
My conclusion: According SAH one should be careful that the parshiyos are totally inside each ones bayis, not descending at all into the titura area, not in the rosh nor in the yad tefilin. It seems to me that such tfilin will be pasul.
This is an understanding in SAH. It is known that there are other opinions in the details mentioned, and Shaivet Halevi vol. 3:3 is meikel in this question.