And this is what Wiki had to say:
The phrase appears in the works of Persian Sufi poets, such as Sanai and Attar of Nishapur. Attar records the fable of a powerful king who asks assembled wise men to create a ring that will make him happy when he is sad, and vice versa. After deliberation the sages hand him a simple ring with the words "This too will pass" etched on it, which has the desired effect.
Jewish folklore often casts Solomon as either the king humbled by the proverb, or as the one who delivers it to another. Many versions of the folktale have been recorded by the Israel Folklore Archive at the University of Haifa. In some versions the phrase is simplified even further, appearing as only the Hebrew letters gimel, zayin, and yodh, which begin the words "Gam zeh ya'avor" (Hebrew: גם זה יעבור, gam zeh yaavor), "this too shall pass."
In Turkish folklore, the phrase is commonly used in short stories and songs. The use of this phrase in colloquial Turkish is thought to have its roots in these songs and stories.
The story, generally attached to a nameless "Eastern monarch", became popular in the West in the first half of the 19th century, appearing in American papers by at least as early as 1839. In 1852, the English poet Edward Fitzgerald included a brief version in his collection Polonius: A Collection of Wise Saws and Modern Instances. Fitzgerald's unattributed version, titled "Solomon's Seal", describes a sultan requesting of King Solomon a sentence that would always be true in good times or bad; Solomon responds, "This too will pass away". On September 30, 1859,Abraham Lincoln included a similar story in an address before the Wisconsin State Agricultural Society in Milwaukee:
It is said an Eastern monarch once charged his wise men to invent him a sentence, to be ever in view, and which should be true and appropriate in all times and situations. They presented him the words: "And this, too, shall pass away." How much it expresses! How chastening in the hour of pride! How consoling in the depths of affliction!
So there you have it, Oppenheimer was not entirely right about the origin of the phrase but the words will stick with you I promise.