Support my clue Angel oddly rejected for 'flammable gas' (9)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

Support my clue Angel oddly rejected for “ flammable gas ” PROP (=support, hold up) + <m> Y <c> L <u> E <a> N <g> E <l> (“oddly rejected” means that all odd letters are dropped)