Robert

“Angel Bob: Doctor? Excuse me, hello, Doctor? Angel Bob here, sir.
The Doctor: Ah, there you are, Angel Bob. How's life? Sorry, bad subject.
Angel Bob: The Angels are wondering what you hope to achieve.
The Doctor: Achieve? We're not achieving anything. We're just hanging, it's nice in here: consoles; comfy chairs; a forest... how's things with you?
Angel Bob: The Angels are feasting, sir. Soon we will be able to absorb enough power to consume this vessel, this world, and all the stars and worlds beyond.
The Doctor: Yeah, but we've got comfy chairs. Did I mention?
Angel Bob: We have no need for comfy chairs.
The Doctor: [amused] I made him say 'comfy chairs'.”
― Steven Moffat

“When you run with the Doctor, it feels like it'll never end. But however hard you try you can't run forever. Everybody knows that everybody dies and nobody knows it like the Doctor. But I do think that all the skies of all the worlds might just turn dark if he ever for one moment, accepts it. Everybody knows that everybody dies. But not every day. Not today. Some days are special. Some days are so, so blessed. Some days, nobody dies at all. (In the library, the Doctor walks back to the TARDIS. He stops, looking at the doors. Then he raises his hand, and stands there poised like that for a long moment. Finally he snaps his fingers. The doors open. He smiles slowly and walks in, joining Donna. Then he snaps his fingers again, and the doors close. River's voice continues over this.) Now and then, every once in a very long while, every day in a million days, when the wind stands fair, and the Doctor comes to call... everybody lives.”
― Steven Moffat

“Amy Pond: 'I thought... well, I started to think you were just a madman with a box.'
The Doctor: 'Amy Pond, there's something you better understand about me, 'cause it's important and one day your life may depend on it. [He Smiles] I am definitely a madman with a box.”
― Steven Moffat

“Demons run when a good man goes to war
Night will fall and drown the sun
When a good man goes to war

Friendship dies and true love lies
Night will fall and the dark will rise
When a good man goes to war

Demons run, but count the cost
The battle's won, but the child is lost”
― Steven Moffat