Beatles thoughts:
This song was John Lennon's declaratory philosophy. The word is Love, and this statement song became the moral choice at the center of songs that followed after Rubber Soul. 'All You Need Is Love' etc. He tells us in this song “say the word and you’ll be free” meaning Speak Love, and free yourself from fear and insecurity. For John, Love meant to be empathetic, kind, and thoughtful of others individually and as a whole. How nice that speaking Love as a rule leads straight to release from insecurity.