Hours before the Tennessee shooting that killed five U.S. servicemen, the suspected gunman texted his close friend a link to an Islamic verse that included the line: "Whosoever shows enmity to a friend of Mine, then I have declared war against him." The friend, who requested anonymity, showed the text message to Reuters on Saturday. He said he thought nothing of the text at the time, but now wonders if it was a hint at Thursday's attack. The suspect, Mohammod Youssuf Abdulazeez, was killed in the gunfight in Chattanooga on Thursday. Abdulazeez's friends said he returned from a trip to Jordan in 2014 concerned about conflicts in the Middle East and the reluctance of the United States and other countries to intervene. He purchased three assault rifles on an online marketplace that he used for target practice, the friends said. "He expressed that he was upset about (the Middle East). But I can't imagine it drove him to this," said the friend who received the text message. U.S. investigators are focusing on Abdulazeez's travels to the Middle East. The FBI is investigating the Chattanooga shooting as an act of domestic terrorism, though law enforcement officials said it was premature to speculate on the gunman's motive. Authorities said Abdulazeez sprayed gunfire at a joint military recruiting center in a strip mall in Chattanooga, then drove to a Naval Reserve Center about 6 miles (10 km) away, where he killed four Marines before he himself was shot dead. Three other people were injured, including a U.S. Navy petty officer who died from his wounds on Saturday. The Navy did not give the name of the sailor, but his step-grandmother identified him as Navy Petty Officer 2nd Class Randall Smith of Paulding, Ohio, who left behind a wife and three young daughters. "He was an awesome young man," Darlene Proxmire told Reuters. "He loved his wife and children. He loved the Navy." GUNS, FAST CARS Abdulazeez's friends, who asked not to be identified for fear of a backlash, said he was upset about the 2014 Israeli bombing campaign in Gaza and the deteriorating civil war in Syria. "He felt Jordan, Qatar, Saudi Arabia were not doing enough to help, and that they were heavily influenced by the United States," said the friend who received the text message. Another friend said, "He had always talked about it, but I'd say his level of understanding and awareness really rose after he came back." Abdulazeez, who was born in Kuwait to Palestinian parents, purchased three guns on armslist.com after returning from Jordan including an AK-74, an AR-15, and a Saiga 12, his friends said. Over the past few months, Abdulazeez and his friends practiced shooting in the Prentice Cooper state forest near Chattanooga, sometimes two or three times a week. Two nights before the attack, Abdulazeez and some friends went joy riding in the hills surrounding Chattanooga in Abdulazeez's rented gray convertible Mustang, passing through the towns of Whitwell, Dayton and Jasper, the friends said. Driving on the narrow tight turns was a favorite pastime. "Fast car on a rainy night. We were flying, doing tight turns and drifting," said the friend who received the text message. They returned home at about 3 am, he said. "He seemed totally normal. We made plans to hang out on the weekend," the friend said. The night before the attack, Wednesday, Abdulazeez sent the text message with the link to a Hadith, or Islamic teaching, a move that the friend said was unusual. "I didn't see it as a hint at the time, but it may have been his way of telling me something," the friend said, adding he had been asking Abdulazeez for job advice. Reuters reviewed the text message, which was sent just after 10pm on Wednesday. The friend, who said he has been interviewed by the Federal Bureau of Investigation, continued to text Abdulazeez that evening and into Thursday but received no other responses.