What is self-talk, and how do I know it's self-talk?

Allah overlooks for a person what he thinks about and the intrusive thoughts he experiences during prayer and at other times, as long as he does not act upon them or speak about them; this is based on the Prophet’s (peace and blessings of Allah be upon him) statement: “Indeed, Allah has overlooked for my Ummah what they think about to themselves, as long as they do not act upon it or speak about it.”