Welcome to the community.
As it is against the rules of this community for individuals to swap personal details I can't see that it would be possible for anyone here to arrange to loan your friends husband a cushion.
I totally agree with Sam_Scope that if he has been discharged without equipment that is essential for him to appropriately positioned then he needs to be talking to the professionals (probably the Occupational Therapist) to see if they can provide him with something suitable or advise him specifically what he needs and where to obtain it.
However, I do recognise that that in this era of stretched resources it can be more difficult than it once was to get none essential equipment from the NHS/local authority, especially if the person's condition is considered temporary because they are expected to make a recovery.
In your area the Red Cross run a service aimed at trying to support people that are recuperating, if your friends husband can't get the support he needs from the NHS or local authority adult services it might be worth giving the Red Cross a call:
Jean Merrilees BSc MRCOT
You can read more of my posts at: https://community.scope.org.uk/categories/ask-an-occupational-therapist