פירוש על גיטין 12:7

Rav Yitzhak said two [words, you can] write [without lines] - The Hilchot Gedolot decides [the Halacha] like Rav Yitzhak. Even though [Rav Yitzhak] argues on a Mishna, [The Hilchot Gedolot] knew that it was not important.

Rabbeinu Tam says and Riva [Rabbeinu Yitzhak ben Asher] also explains in the name of Rabbeinu Eliahu that specifically when he intends to write the verse to expound upon it [the rule of Rav Yitzhak applies] as in our case. But when a person sends a letter to his friend, it is permissible to write the text of scripture, in order to write with proper grammar, without lines.

However in the Yerushalmi the last chapter of Megillah slightly implies that [the rule of Rabbeinu Tam] is forbidden. It says [in the Yerushalmi] What is the law to write two or three words from a verse? It is brought: Rav Mona sent a letter to Rav Oshia bar Shimi [the letter quoted Job 8:7 with the words scrambled] "Though your beginning be small, In the end you will grow very great". It is implied [Rav Mona] only wrote [this] as a friendly letter and not to expound upon it and even so [Rav Mona] was careful to write it out of order. [Thus implying that if the verse was in order it would still require lines even though it was in a friendly letter] However many bring there that it appears they would write [the verse] to expound upon it [even when the verse was scrambled]. Because it says: Mar Ukva sent a letter to the exilarch (the exilarch would awaken and sleep with song. He explained that when [the exilarch] would lie down and get they would sing before him): "Rejoice not, O Israel, As other peoples exult"(Hosea 9:1) And so many people bring there [that a scrambled verse is not immune from being expounded upon]

If you will say, that it is said in Menachot 32b and in Megillah 18b: Tefilin do not need to be lined. Did we not [just] say that three or four words [from scripture] must be lined? Rabbeinu Tam says don't line Tefilin on every single line, as it is said in the Yerushalmi Shabbat chapter 2: Anyone who is exempt from something and [still] does it is called an idiot. This is also implied in Menachot 32b, because it says there: Tefilin do not need lines. And it is asked from a Braita: A Torah scroll or Tefilin that are worn out we don't make mezuzot from them because we don't go from a hard holiness to a weak holiness. What if we can go down [in holiness]? [It's still forbidden because] a Mezuzah needs to be lined [and Tefilin are not lined]. [whether or not Mezuzah needs to be lined is a Tannaic dispute] [Which opinion does our braita] deal with? With [Mezuzot] that are lined. It is implied that it is not common to line Torah Scrolls or Tefilin, and this is because [if one lines them,] he is called an idiot. However if the scribe is unable to write neatly without lines, he must line every single line because [of the verse] "This is my God and I will enshrine Him"(Exodus 15:2). Doesn't it say in Megillah 17b: "an ordinance of “equity and honesty:”"(Esther 9:30)? This teaches [us] that lines are needed according to the "truth" of Torah. Rabbeinu Tam says There was never a Torah scroll that did not require lines. Rather this [law from Megillah] is regarding Mezuzah, and [Mezuzah] is called the "truth" of Torah because it contains the singular name of the kingdom of heaven. Rabbeinu Hananel also explained: So it appears That a Torah Scroll that we make unusable according to the Kuntares in Megillah 19a because it is written on unfinished parchment or without black ink, [This law] is derived from [a Gezeirat Shavah (identity)] two mentions of writing. as it says "and I would write them down in the scroll in ink." (Jeremiah 36:18) Why don't we learn [this law of proper parchment and ink] from the "truth" of Torah . . .