blindfold your child at bed time and put him to bed. Can he feel how many soft toys you give him to cuddle? Ask him to feel them and guess which ones they are? You should probably use a sleep mask not a scarf. Just make sure he cannot see what he is cuddling.
Or after washing day, make your child’s bed and guide him into the room blindfolded, guide him to feel the bed clothes, and guess what they are.