What are A pocket full of mumbles such are promises What are 'mumbles'?

Answer 1

In this case, as written by Paul Simon, mumbles are promises. As in, he gave in or compromisedsquandered his resistance") to promises made which were, in fact, "all lies and jest." A pocket full of mumbles are a poetic use of how he might have otherwise written "a bunch of promises." He completes the phrase with "still a man hears what he wants to hear and disregards the rest, meaning a man hears promises and believes those promises even though they were but deceit ("lies and jest").

I hope this is helpful...

Paul