According to our earliest detailed biographical source on Muhammad's life, Islam's prophet once ordered his followers to torture a man for money. Here's the passage:
Kinana b. al-Rabi, who had the custody of the treasure of Banu al-Nadir, was brought to the apostle who asked him about it. He denied that he knew where it was. A Jew came to the apostle and said that he had seen Kinana going round a certain ruin every morning early. When the apostle said to Kinana, "Do you know that if we find you have it I shall kill you?" he said Yes. The apostle gave orders that the ruin was to be excavated and some of the treasure was found. When he asked him about the rest he refused to produce it, so the apostle gave orders to al-Zubayr b. al-Awwam, "Torture him until you extract what he has," so he kindled a fire with flint and steel on his chest until he was nearly dead. Then the apostle delivered him to Muhammad b. Maslama and he struck off his head, in revenge for his brother Mahmud. (Ibn Ishaq, Sirat Rasul Allah, p. 515)
Following this brutal spectacle, Muhammad took Kinana's seventeen-year-old wife, Safiyya bint Huyayy, as his own bride (because nothing says lovin' like torturing and murdering a woman's husband for money).