[Help-bash] trap -p puzzle

[Peter West]

$ trap -p USR1
trap -- ‘rm rhubarb’ SIGUSR1
$ trap -p USR1 >f
$ cat f
trap -- ‘rm rhubarb' SIGUSR1
$ cat f|hexdump -C
00000000  74 72 61 70 20 2d 2d 20  27 72 6d 20 72 68 75 62  |trap -- 'rm rhub|
00000010  61 72 62 27 20 53 49 47  55 53 52 31 0a           |arb' SIGUSR1.|
0000001d
$ trap -p USR1 | hexdump -C
$

Que?

Peter West
"Why do you seek the living among the dead? He is not here, but has risen."