If I forget thee, O Jerusalem

Psalm 137 contains the phrase "אם אשכחך ירושלים תשכח ימיני - If I forget you, O Jerusalem, let my right hand forget".

Jonah and I were discussing why today, the 9th of Av, is such a sad day. I asked him why it is a sad day and he told me because the" בית המקדש נרשף, the Holy Temple burnt."
I asked if he knew the song "אם אשכחך" and if he knew what it meant (see translation above).

He told me, "Well, Mommy, I'll always remember Yerushalyim, but sometimes I forget which is my right hand."

May everyone have an easy and meaningful fast and may this day next year be one of celebration at our Holy Temple in Jerusalem.