Sample of Joseph's private language from 1840 (a holographic letter).
Joseph Smith, Letter to Newel K. Whitney, December 12, 1840, The Joseph Smith Papers website, accessed August 18, 2023
Nauvoo Dec. 12th 1840
I am at work in my office am under the necesity to have some help from time to time to help me along in my calling I therefore desire you to let the bearer of this hav[e] <some> of that dry wood to burn in the stove of my office and obliege
your hum[b]le servent