tanach - General understanding of Kri and Ktiv

A number of questions regarding the 'kri and ktiv'

1. What is the source (talmudic or otherwise) for this concept?


2. Why is it necessary; meaning why could we not adduce whatever concept is being taught by having both the kri and ktiv in another way?


3. Is there a halachik source that contains a full list of all kri/ktiv pairing in all of tanach?


4. (possibly a subset of the above) Do all branches of orthodoxy have the exact same list?

related

Answer

1. 
   

   The Gemara (Megillah 25b) mentions several examples of one type of keri ukesiv - where a less refined word is replaced with a more euphemistic one. (Examples include ובעפלים\ובטחרים in Deut. 28:27, ישגלנה\ישכבנה ibid. v. 30, and several others in Nach.)

   
   
   

   In various scattered places (examples include Eruvin 26a, Yoma 21b and Sotah 42b) it also mentions others (using the expression ...כתיב... וקרינן), although this expression is also used for cases of יש אם למקרא vs. למסורת such as those mentioned in moses' answer (as in Pesachim 26b/Bava Metzia 30a, Yoma 72b, 75b and 76b, and many others).

   
   


2. 
   

   Not quite certain what you mean by this, although the answers in the question I linked in my comment give several different reasons provided in the sources for the existence of this phenomenon.

   
   


3. 
   

   Minchas Shai is a pretty generally accepted authority on masoretic matters, including keri ukesiv. However, he doesn't (AFAIK) have a list of just the k.u.k. pairs, and I don't know whether there's any classical source that does so.

   
   


4. 
   

   There are indeed variations between different versions of the masorah. As one example, see Minchas Shai to Ps. 24:4 for a long discussion of whether the eighth word in that verse is supposed to be נפשי,‎ נפשו, or one or the other of these serving as kesiv and the other as keri.