$ bitcoin-cli getblock 666666
...
057954bb28527ff9c7701c6fd2b7f770163718ded09745da56cc95e7606afe99
....
$ bitcoin-cli getrawtransaction 057954bb28527ff9c7701c6fd2b7f770163718ded09745da56cc95e7606afe99
01000000000101ff133ad017deef.......103070e0d1380e355f13ce8f58283c1bdd53d2bfd667db1982ca2c8c51578596d6e00000000
bitcoin-cli decoderawtransaction 01000000000101ff133ad017deef.......103070e0d1380e355f13ce8f58283c1bdd53d2bfd667db1982ca2c8c51578596d6e00000000
"asm": "OP_RETURN 446f206e6f74206265206f766572636f6d65206279206576696c2c20627574206f766572636f6d65206576696c207769746820676f6f64202d20526f6d616e732031323a3231",
$ echo -e "$(echo "446f206e6f74206265206f766572636f6d65206279206576696c2c20627574206f766572636f6d65206576696c207769746820676f6f64202d20526f6d616e732031323a3231" | xxd -r -p)"
Do not be overcome by evil, but overcome evil with good - Romans 12:21