אַרְבָּעִ֥ים יַכֶּ֖נּוּ לֹ֣א יֹסִ֑יף פֶּן־יֹסִ֨יף לְהַכֹּת֤וֹ עַל־אֵ֙לֶּה֙ מַכָּ֣ה רַבָּ֔ה וְנִקְלָ֥ה אָחִ֖יךָ לְעֵינֶֽיךָ׃ (ס)
Quaranta strisce che può dargli, non deve superare; se non dovesse eccedere, e batterlo sopra di loro con molte strisce, allora tuo fratello dovrebbe essere disonorato davanti ai tuoi occhi.
Zohar
Rabbi Yosi said that the instant the Holy One blessed be He, resurrects the dead, all troubles will end, on the fortieth year (after the gathering of the exiles). It has been resolved by law "Forty stripes he may give him, and not exceed" (Devarim 25:3). The journey of Yisrael in the desert (was finished) in the fortieth year. Forty years before the body is resurrected, the soul awaits it in the land of Yisrael. In the fortieth year, the bodies will rise from the dust. After forty days the rain stopped, this is the meaning of the verses "And the rain was upon the earth forty days and forty nights" (Gen. 7:12), and "it came to pass at the end of forty days, that Noah opened" (Gen. 8:6). Also, the time of the Redemption of Yisrael is during the fortieth year. During the fiftieth year, the world, which is Jubilee, will be populated. The return of the soul to the body occurs after forty years of waiting in the land of Yisrael. This is the meaning of, "and Isaac was forty years old." That is, he was waiting for the body. "When he took Rivkah," who was put in the body prepared for him. Their passion and longing at that moment was for the splendor of the Shechinah only and to nourish of Her splendor. This is the meaning of the verse, "Let him kiss me with the kisses of his mouth." Rabbi Abba said, "Let him kiss me" means let him nourish me. Their sole nourishment is the enjoyment and sustenance of the supernal splendor. Rabbi Yosi said that this is proven by the end of the verse, which reads, "for your love is better than wine" (Shir Hashirim 1:2).
Zohar
"For in another seven days, I will cause it to rain upon the earth forty days and forty nights" (Gen. 7:4). Rabbi Yehuda said: What is the meaning of these forty days and forty nights? These forty days are to strike the wicked of the world, as is written: "forty strikes he may give him, and not exceed" (Devarim 25:3), corresponding to the four winds of the world. As each one has ten (there are thus 40). For man was created from the four winds of the world. So, the verse continues: "And every living substance that I have made will I destroy from the face of the earth." Forty strikes are needed to destroy the world.