A British Islamist preacher has been recorded justifying beheadings of non-Muslim captives by the brutal Islamic State (ISIS) organization – and even suggests that all able-bodied non-Muslim men are legitimate targets for murder.

In a video obtained by the Middle East Media Research Institute (MEMRI), Minazur Rahman relates to the recent beheading of British aid worker Alan Henning by ISIS – an act which generated opposition even from many conservative Muslims, who noted that Henning was in Syria to help Muslim victims of the Assad regime’s bloody campaign.

Jumping to defend ISIS’s actions, Rahman – who was jailed for four years in 2007 for soliciting murder – claimed that under Muslim law (sharia) “a combatant is… any adult, mature, capable kaffir (infidel) man.”

“If he has no covenant of security with the Muslims, he is called a combatant… it’s not ‘did he fight,’ it’s about ‘is he capable to fight’,” he said.

That definition excludes women, children, the elderly and disabled, he added. Later in his speech, however, Rahman noted that women and children of non-Muslims should be taken “as slaves.”