He wrote the letter in German (translation below) to help it get past the censors. The letter reveals that his prisoner number was 100379 and that he was in cell block 41. Note his good cheer though he knew he was near death.
Oranienburg, Sachsenhausen, my dearest Regina and all of you. Trying to reach you by this letter; should it arrive, please write me. Still in good health and cheerful. Work is not heavy; sufficient clothing. But less food. Until now God has helped me. Pray that I may be permitted to return my love to you. Jan Bruinsma [brother-in-law] has been here, too. Healthy, but you’ll be suffering hunger and cold. Hope and pray that you’ll get through it all. Winter has started, but it’s not too cold. Still sleeping well. Prayer and consolation: Ps 25 Forgive my transgressions for thy goodness sake. Though in grievous suffering my heart and flesh may fail, Ps 73, as in Romans, in all these we are more than conquerors. Longing for you and news. That is a strengthening bond. Greetings to family, friends, (and) dear grandchildren. I can see Jaapje [grandson] before me. Am always praying for you. Our prayers join one another. May God protect you. I am in His school. All earthly things pass away. Life and love are everlasting. Greetings to all. Your loving T'.
For the full story of Taeke's arrest, imprisonment and death, please see here.