A bidding war lasted four minutes, the New York Times reported, and ended with the letter selling for $2,892,500—nearly double what the auction house had estimated the piece would sell for, which was between $1 million to $1.5 million. The winning bidder wasn’t identified.

Prior to Tuesday’s sale, the highest price the Manhattan auction house had seen for one of Einstein’s letters was $2.1 million in 2008, the paper reported. That typed 1939 letter was sent to President Franklin D. Roosevelt cautioning him on the creation of “powerful bombs,” according to the New York Times.

Eric Gutkind, a German philosopher, wrote a book “Choose Life: The Biblical Call to Revolt,” which prompted the letter from Einstein. The page-and-a-half long letter, dated 1959, was written a year before Einstein’s death.

“The word God for me is nothing but the expression of and product of human weakness, the Bible a collection of venerable but still rather primitive legends,” the letter reads.

The Gutkind family owned the letter until 2008 when it was auctioned for $404,000.

Christie’s called the letter “the most fully articulated expression of his religious and philosophical views.”

However, Walter Isaacson, an Einstein biographer, isn’t so sure. Einstein, described as a proud Jew, had many pieces of writings that were inconsistent on the topic of higher power and religion, Isaacson said, adding that the “God letter” shouldn’t solely represent his beliefs.