Bereishit 23:1
Vayihyu chayei Sarah - The lifetime of Sarah was.
Just before this verse the Torah states, And Betuel begot Rivkah (22:23).  For it was while Sarah's sun had not yet set, that Rivkah's sun rose.  This is alluded to in the initial letters of the words Sarah meah shanah - Sarah.... one hundred years, which spell shemesh, sun.  And this is the lesson of the verse, And the sun shines and the sun sets (Kohelet 1:5).
Must Scripture tell us the sun shines and the sun sets?  The verse must be understood as a parable:
Before G-d allows the sun of a righteous leader to set [i.e., before that leader's demise], He causes the sun of another righteous leader to rise [i.e., his successor enters the world].  Thus, on the day that Rabbi Akiva died, Rebbi [Yehudah HaNassi] was born... On the day Rabbi Ada bar Ahavah died, Rabbi Avun was born.
Examples of a similar phenomenon, the appointment of a successor during the first leader's lifetime, are:
Before G-d caused Moshe's sun to set, He caused Yehoshua's sun to rise, as it is stated, Hashem said to Moshe, "Take to yourself Yehoshua son of Nun..." (BaMidbar 27:18)
Before G-d caused Sarah's sun to set, He caused Rivkah's sun to rise, thus, it is stated, Behold! Milkah too has born children... [and Betuel begot Rivkah] (22:20-23), and then [the verse speaks of Sarah's passing.]  Sarah's lifetime was one hundred years... (Bereishit Rabbah 52:8; Kohelet Rabbah 1:5; also Kiddushin 72b).
Shenei chayei Sarah - The years of Sarah's life.
The verse does not say, yemei [chayei Sarah] the days of [Sarah's life], because [in order for her to conceive and bear Yitzchak] she had been rejuvenated and had been returned to the days of her youth.  When she became still older, those youthful days ceased.  Therefore the verse states, shenei chayei Sarah, the years of [Sarah's life], which can also be understood as, the two [lives of Sarah].
In recounting people's ages the Torah usually uses the term yemei chayei, the days of the life of... (see 5:8, 11, 14).  Regarding seven people, however, the term shenei chayei, the year of the life of..., is used:
  1. Sarah (23:1)
  2. Avraham (25:7)
  3. Yishmael (25:17)
  4. Yaakov (47:8,9, 28)
  5. Levi (Shemot 6:16)
  6. Kohat (Shemot 6:18)
  7. Amram (Shemot 6:20)
*Note: Baal HaTurim explains why shenei and not yemei, is used regarding Sarah.  Curiously, he makes not attempt to explain the others.  Perhaps, the Baal HaTurim ignores the word shenei regarding Avraham and Yaakov because each of the verses there uses yemei as well as shenei.  Regarding Yishmael, he makes no comment because there, like here, the word could be seen as meaning two.  For Yishmael also lived "two" lives, as the Talmud teaches: Yishmael repented the evil of his ways (Bava Batra 16b).  Thus, he lived two lives, one wicked, one righteous.   Regarding Levi, Kohat and Amram, the Baal HaTurim does not comment, for as Rashi (Shemot 6:16, 18) explains, it is not the Torah's purpose to reveal the respective ages of these three; rather, their ages are mentioned as time frames by which to determine the exact number of years during which the Yisraelim were subjected to slavery in Egypt.  Thus shenei is the more appropriate word (VeChur LaZahav).
Vayakam Avraham meal penei meto vayedaber el benei Chet - And Avraham rose from the presence of his dead, and spoke to the children of Chet.
This, the order of Avraham's actions, first rising and leaving the presence of his dead wife, then speaking, teaches that it is forbidden to speak in the presence of a corpse.  The verse could have stated simply, And Avraham spoke to the children of Chet, without telling us that he first rose from the presence of his dead.  By adding the extra clause, the Torah teaches that generally it is not permitted to speak in the presence of the deceased (VeChur LaZahav).
The term benei Chet, the children of Chet, appears ten times in this passage (here 8 times - v3, 5, 7, 10 [twice], 16, 18, 20, and two more in 25:19 and 49:32), for anyone who clarifies the acquisition of property by a Torah sage is considered to have fulfilled the Ten Commandments, in which the letter chet appears ten times.
Metecha - Your dead.
This word appears four times in the Tanch, three times here (twice in v6 and once in v11); and once in Yeshayahu 26:19 - your dead will come to life...  Three times in this pasasge are spelled defectively [without a yud], for they refer to only one deceased person.  The verse in Yeshayahu, by contrast, is spelled in full [with a yud], for it is speaking about many dead people. 
There is an allusion here to the Sages' statement:  The dead in Eretz Yisrael will be resurrected first (Yerushalmi, Kilayim 9:3).  For the term metecha, your dead, of the verse [which speaks of Eretz Yisrael], and the term yichyu meteicha , your dead will come to life, of the verse in Yeshayahu [which speaks of thosde who died ini all the ends of the earth - v.16] can be interpreted in tandem:  Those dead who are buried here [in Eretz Yisrael] will resurrect those dead who are buried there [in the diaspora] (Rabbi Yehudah HaChassid; Ketubot 111a; Bereishit Rabbah 96:5)
- Baal HaTurim