I did some reading on where this term came from. I came across this story, which I thought was rather sweet.

The Persian Legend of “This Too Shall Pass”

Long ago, a mighty Persian king gathered his wisest advisors and set them an impossible task.

“Find me a truth,” he commanded, “a single phrase that is always true—something that will bring me peace in sorrow and humility in joy.”

The advisors consulted scholars, poets, and mystics, searching for words that held wisdom in all situations. After much deliberation, they returned to the king, presenting him with a simple inscription:

“This too shall pass.”

The king studied the phrase, puzzled at first.

The advisors explained:

When you are overwhelmed with grief, remember: this too shall pass. No sorrow lasts forever.

When you are basking in triumph, remember: this too shall pass. Fortune is fleeting, and humility is wisdom.

The king was deeply moved. He had sought wisdom, expecting complexity, but found the greatest truth in its simplicity. From that day forward, he wore the phrase inscribed on a ring, turning it over in his hand whenever he faced great joy or deep despair.

And so, the lesson endured: all things—good and bad—are temporary.