The day will come when HaShem will, in the blink of an eye, turn Tisha B’Av from the day of our greatest sorrow to the day of our greatest joy. We will no longer observe the day in sorrow, but with a great festival! May this day come soon and in our days.

What is the proof, you ask?

The Arizal writes that the numerical value of ‘Dimah–Tears’ is 120, which in Torah signifies full life. In truth, the letters only add up to 119, but when the word ‘Dimah’ as a whole is counted, it equals 120. The Shomer Emunim explains that for certain concepts the whole is greater than the sum of the parts. In such cases, you also factor in the entire word to indicate a higher purpose that brings meaning to all the details.

Maimonides explains in his Laws of Mourning that the purpose of mourning and tears is repentance. Death only came into this world through sin, and it is through repentance that the world will be restored to its original state of eternal life, when “G-d will wipe away the tears from every face.”

Maimonides concludes his Laws of Fasts: “With the Redemption, all these days of mourning will be transformed into days of rejoicing, into days of good Moed.” Dimah plus 1, equals 120, which is the exact numerical value of Moed!

(From the shiur by Rebbe Menachem Mendel Schneerson on 20 Menachem Av, 5742 · August 9, 1982)

Tehillim (Psalms) 30: 6 For His anger is but for a moment, His favour is for a life-time;
weeping may tarry for the night, but joy cometh in the morning.