Crustless toast on income support in refuge (5)

I believe the answer is:
oasis
'refuge' is the definition.
(I've seen this before)
'crustless toast on income support' is the wordplay.
'crustless toast' becomes 'oas' (I can't explain this - if you can you should believe this answer much more).
'on' says to put letters next to each other (in a down clue, letters appear on others).
'income support' becomes 'IS' (abbreviation for income support).
'oas'+'is'='OASIS'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for oasis that I've seen before include "A place of safety or sanctuary" , "English rock group in the desert" , "Desert refuge" , "provides refuge" , "Fertile place in a desert, watering-hole" .)
