'Heavy' in the Bible

“Son of man, Nebuchadnezzar king of Babylon made his army work hard [at My command] against Tyre; every [soldier’s] head became bald and every shoulder was worn and peeled [from carrying loads of dirt and stones for siege works]. Yet he had no wages from Tyre [in proportion to the time and labor expended during the siege], either for himself or his army, for the work that he had done against it [for Me].”