bris k'rusa li'sefasayim -- words shape reality

וְעַתָּ֗ה אֶֽעֱלֶה־נָּ֛א וְאֶקְבְּרָ֥ה אֶת־אָבִ֖י וְאָשֽׁוּבָה׃... (50:5)  Why stick in the extra word וְעַתָּ֗ה?  We have a concept of "al tiftach peh l'satan."  Don't tempt fate.  If you show that you are not concerned with a potential kitrug, then you are inviting that kitrug.  There is another similar concept called "bris kerusa l'sefasayim."

   מנין שברית כרותה לשפתים – שנאמר (בראשית כ''ב, ה'): וַיֹּאמֶר אַבְרָהָם אֶל נְעָרָיו שְׁבוּ לָכֶם פֹּה עִם הַחֲמוֹר וַאֲנִי וְהַנַּעַר נֵלְכָה עַד כֹּה וְנִשְׁתַּחֲוֶה וְנָשׁוּבָה אֲלֵיכֶם: ואיסתייעא מלתא דהדור תרוייהו. (M"K 18a) 

 

Avraham and Yitzchak returned unharmed from the akeidah just as they said they would, or, to be more exact, because they said they would.  The idea of ברית כרותה לשפתים is, writes Maharasha, like nevuah.  The words that come out of your mouth have tremendous power because they reflect truth.  Therefore, unlike "al tiftach peh l'satan," here it even works to a person's benefit.  R' Shlomo Kluguer in Imrei Shefer writes that this is why Yosef did not want to say just  the words אֶֽעֱלֶה־נָּ֛א ... וְאָשֽׁוּבָה׃  I'm going to go to Eretz Yisrael and will come back -- period, full stop.  You mean that's it?  I come back here, "home" to Egypt, and this where I am going to stay?  ברית כרותה לשפתים  Don't even say such a thing!  Words carry weight.  Instead, וְעַתָּ֗ה אֶֽעֱלֶה־נָּ֛א... וְאָשֽׁוּבָה׃.  Right now, ְעַתָּ֗ה, I will go and will have to come back, but, one day in the future I will go to Eretz Yisrael and not have to come back.  

You know you when you go on your vacation to Eretz Yisrael that you already have a return ticket booked to come "home," but at least when you talk about it, let the trip be וְעַתָּ֗ה אֶֽעֱלֶה־נָּ֛א... וְאָשֽׁוּבָה׃, now I am going and will return. The future hopefully holds something different, a time when we will all go and not have to return anywhere else.  

Yosef's care in his every word is something he got from his father. Earlier in the parsha, Yaakov has Yosef swear that he will ensure that he is buried in me'aras ha'machpeila. Yaakov tells Yosef וַאֲנִ֣י׀ בְּבֹאִ֣י מִפַּדָּ֗ן מֵ֩תָה֩ עָלַ֨י רָחֵ֜ל בְּאֶ֤רֶץ כְּנַ֙עַן֙ בַּדֶּ֔רֶךְ בְּע֥וֹד כִּבְרַת־אֶ֖רֶץ לָבֹ֣א אֶפְרָ֑תָה וָאֶקְבְּרֶ֤הָ שָּׁם֙ בְּדֶ֣רֶךְ אֶפְרָ֔ת הִ֖וא בֵּ֥ית לָֽחֶם. Some read this as Yaakov asking forgiveness of Yosef for not ensuring that his mother is buried there. Meshech Chochma connects Yaakov's words here with the Midrash which explains the reason for Rachel's death is because Yaakov did not make haste to fulfill the vow to return home that he had made when he departed for Lavan's home 

 ורבנן אמרי כל מי שנודר ומשהה נדרו קובר את אשתו הה״ד: ״ואני בבואי מפדן מתה עלי רחל.

Yaakov was hinting to Yosef that he should not delay fulfilling the vow to bury him in Eretz Yisrael as he knows first hand that the danger that can come from such action. You make a promise -- keep your word and take care of it right away.  On an even simpler level, Rashi at the end of VaYeitzi gives a different reason for Rachel's death. Since Yaakov said to Lavan עִ֠ם אֲשֶׁ֨ר תִּמְצָ֣א אֶת־אֱלֹהֶ֘יךָ֮ לֹ֣א יִֽחְיֶה֒, he inadvertently invited trouble. וְלֹֽא־יָדַ֣ע יַעֲקֹ֔ב כִּ֥י רָחֵ֖ל גְּנָבָֽתַם says the pasuk, because, as the Bechor Shor explains, had Yaakov known, those words לֹ֣א יִֽחְיֶה֒ would have never come out of his mouth. ברית כרותה לשפתים! Perhaps Yaakov meant to tell Yosef that if this is the power of words, kal v'chomer he should be extra careful to make sure to fulfill his promise to bury Yaakov. Now, when the time has come for Yosef to fulfill that promise, he remembers the lesson ברית כרותה לשפתים that his father was trying to impart.  He is therefore extra careful with his own words.

I think this sheds light on the penultimate pasuk in the parsha, וַיַּשְׁבַּ֣ע יוֹסֵ֔ף אֶת־בְּנֵ֥י יִשְׂרָאֵ֖ל לֵאמֹ֑ר פָּקֹ֨ד יִפְקֹ֤ד אֱלֹקים֙ אֶתְכֶ֔ם וְהַעֲלִתֶ֥ם אֶת־עַצְמֹתַ֖י מִזֶּֽה (50:25). Rabeinu Bachyei is medayek that the pasuk doesn't say וַיַּשְׁבַּ֣ע יוֹסֵ֔ף אֶת אחיו, but rather it refers to בְּנֵ֥י יִשְׂרָאֵ֖ל. Yosef meant to include in his oath anyone who would in the future be part of Bnei Yisrael, not just his immediate brothers. So who is the לֵאמֹ֑ר speaking to? There is a Midrash interprets לֵאמֹ֑ר to mean that the Yosef's brothers would administer this same oath their children, and their children to their chidren, etc. until it could be fulfilled. According to Rabeinu Bachyei, all those future generations are automatically be included in the original oath.

 היה הכתוב ראוי לומר וישבע יוסף את אחיו אלא מלמד שהשביע לכל מי שהוא מבני ישראל ואפילו העתידים להיות.

So why do you need the לֵאמֹ֑ר in the pasuk? I think that even according to Rabeinu Bachyei, the Midrash's interpretation, that Yosef was telling his brothers to speak to future generations, works. Yosef's goal was not just to bind future generations to keep the promise he made them give.  Yosef's goal was to enable them to do so.  Yosef wanted to give future generations the hope and inspiration to survive the galus so that one day there would be a Klal Yisrael who would fulfill their promise to him.  Therefore, he not only had them promise וְהַעֲלִתֶ֥ם אֶת־עַצְמֹתַ֖י מִזֶּֽה, to take his bones out with them, but he had them promise לֵאמֹ֑ר פָּקֹ֨ד יִפְקֹ֤ד אֱלֹקים֙ אֶתְכֶ֔ם, to keep saying to their children, to keep saying to themselves, that they would be redeemed.  It's not enough to believe it.  Yosef wanted them to make that promise into a mantra, לֵאמֹ֑ר, to keep repeating it gain and again.   ברית כרותה לשפתים If you say it, it will become the reality.  That was the message Yosef took from Yaakov as Yaakov's life drew to a close, and that is the message he passed on as his own life ended as well.