And Rabbi Yoḥanan said in the name of Rabbi Shimon ben Yoḥai: From the day the Holy Blessed One created the world, no one thanked the Holy Blessed One, until Leah came and thanked God, as it is stated: “And she became pregnant and gave birth to a son, and she said, ‘This time I will give thanks to God,’ and thus he was called Judah” (Genesis 29:35).
וַיִּזְכֹּר אֱלֹקִים, מַה כְּתִיב לְמַעְלָה מִן הָעִנְיָן, וַתַּהַר עוֹד וַתֵּלֶד בֵּן וַתֹּאמֶר הַפַּעַם אוֹדֶה אֶת ה'. לָמָּה לֹא אָמְרָה בִרְאוּבֵן וְשִׁמְעוֹן וְלֵוִי וּבְכֻלָּם הוֹדָיָה אֶלָּא בִיהוּדָה. מָשָׁל לְכֹהֵן שֶׁיָּצָא לַגֹּרֶן לִטֹּל תְּרוּמָה וּמַעֲשֵׂר, וּבָא בַעַל הַגֹּרֶן נָתָן לוֹ תְרוּמָה וְלֹא הֶחֱזִיק לוֹ טוֹבָה, נָתַן לוֹ מַעֲשֵׂר וְלֹא הֶחֱזִיק לוֹ טוֹבָה. לְאַחַר שֶׁנָּתַן לוֹ כָּל מַה שֶּׁהָיָה רָאוּי לַכֹּהֵן לִטֹּל, עָמַד בַּעַל הַגֹּרֶן וְהוֹסִיף לוֹ מִדָּה אַחַת שֶׁל חֻלִּין. הֶחֱזִיק לוֹ טוֹבָה וְנִתְפַּלֵּל עָלָיו. אָמְרוּ לוֹ: לָמָּה כְּשֶׁנָּתַן לְךָ בַּעַל הַגֹּרֶן הַתְּרוּמָה וְהַמַּעֲשֵׂר לֹא הֶחֱזַקְתָּ לוֹ טוֹבָה, וְעַכְשָׁו עַל מְעַט מִדָּה אַחַת שֶׁל חֻלִּין הֶחֱזַקְתָּ לוֹ טוֹבָה. אָמַר לָהֶן, הָרִאשׁוֹנוֹת הַתְּרוּמָה וְהַמַּעֲשֵׂר, שֶׁלִּי הֵן וְשֶׁלִּי לָקַחְתִּי. אֲבָל אוֹתָהּ הַמִּדָּה שֶׁהוֹסִיף לִי, מִשֶּׁלּוֹ, לְפִיכָךְ אֲנִי מַחֲזִיק לוֹ טוֹבָה. וְכָךְ אָמְרָה לֵאָה, שְׁנֵים עָשָׂר שְׁבָטִים עֲתִידִין לַעֲמֹד מִיַּעֲקֹב, וַהֲרֵי אָנוּ אַרְבַּע נָשִׁים, אָנוּ רְאוּיוֹת לֵילֵד שְׁלֹשָה לְכָל אַחַת וְאֶחָת. שְׁלֹשָׁה שֶׁיָּלַדְתִּי כְבָר, חֶלְקִי הֵן. עַכְשָׁו כְּשֶׁהוֹסִיף לִי בֵּן רְבִיעִי עַל חֶלְקִי, בְּוַדַּאי הַפַּעַם אוֹדֶה אֶת ה'.
And God remembered Rachel. Prior to this verse, it is written: And Leah conceived again, and bore a son; and she said: “This time will I praise the Lord” (Gen. 29:35). Why did she not say I will praise the Lord after the births of Reuben, Simeon, Levi, and all the others, but only after the birth of Judah? This may be compared to a priest who goes to a man’s barn to collect the tithe and the priestly portion. When the owner of the barn hands the priest the priestly portion, he does not thank him, and when he gives him the tithe, he still does not thank him. But if, after he gives the priest what is due him, he adds a measure of unconsecrated food, the priest does thank him and recites a prayer in his behalf. A bystander asked the priest: “Why is it that when he gave you the tithe and the priestly portion, you did not thank him, but when he added only a single measure of unconsecrated food, you thanked him?” The priest replied: “The tithe and the priestly offering belong to me, and I merely accepted that which belonged to me, but the measure of unconsecrated food he added belonged to him, and so I thanked him for it.” Similarly Leah said: “Twelve tribes are to descend from Jacob, and since he has four wives, each of us is entitled to bear three sons. I have already given birth to three sons, my rightful share, but now a fourth son has been granted to me; surely it is fitting that I praise the Lord this time.”
אך באמת נראה, שלכוונה גדולה כוונו אמותינו הצדקניות בזה ולמדו אותנו בזה דרך איך לעבוד להבורא ברוך הוא, ורמזו לנו שני דברים. אחד, שהשם יתברך ברוך הוא אף על פי שהוא מלך גדול ואדיר ואין קץ לשיעור מרכבת כבודו ריבוא רבבות מלאכים ישמשנו אף על פי כן הוא משגיח בהשגחה פרטית על עולם התחתון עולם השפל ומשפיע טובות וברכות לעמו ישראל ולאפוקי מדעת הנפסדת והכוזבת וזה למדו אותנו האמהות הצדקניות לאה במה שאמרה ראה ה' בעניי כי שנואה אנכי, ונמצא למדה אותנו שהקדוש ברוך הוא משגיח עלינו בעולם השפל הזה להשפיע לנו טובות וברכות.
By naming their children, the matriarchs provide us with a model lesson on how to serve the Eternal. Our matriarchs taught us how G’d, the Creator of the universe, in spite of the thousands of concerns that keep God occupied around the clock, never neglects the problems of an individual creature of God on earth. Leah testifies that this Creator took time out to notice that she was relatively hated by her husband as a result of which God granted her children, in spite of her being barren by nature.
Rabbi Shai Held
What makes Leah's gratitude unique; what is it that establishes her as the first truly grateful person?
It is one thing to be grateful when everything is wonderful, when all of our dreams have been fulfilled and all of our hungers sated. But it is quite another to be grateful when life is complicated, when some of our most cherished dreams have remained painfully unrealized, when some of our yearnings are so intense that they threaten to burn right through us. Leah is the first person to feel and express gratitude even and especially amid profound sorrow and enduring disappointment.
Strikingly, the name Leah gives her fourth son, Judah, becomes the name of the Jewish people as a whole -- Jew (Yehudi) comes from the name Judah (Yehudah). Who is a Jew? One who discovers the possibility of gratitude even amid heartbreak. That is why we are given the name that expresses Leah's courage, and her achievement: A Jew, ideally, is a human being who, like Leah, can find her way to gratitude without having everything she wants or even needs.
Disappointment need not preclude gratitude, just as gratitude need not crowd out disappointment. Judaism does not ask us to choose one feeling or the other, but rather makes space -- indeed, seeks to teach us to make space -- for the sheer complexity and contradictoriness of human experience. Who better than Leah to teach us that a broken heart can also have moments of profound fullness?
https://www.huffpost.com/entry/holding-gratitude-and-disappointment_b_4220057
Rabbi Abraham Joshua Heschel
How strange we are in the world, and how presumptuous our doings! Only one response can maintain us: gratefulness for witnessing the wonder, for the gift of our unearned right to serve, to adore, and to fulfil. It is gratefulness that makes the soul great.