The manifesto lists principles. Principles must be implemented and turned into processes in order to actually produce software. Scrum's daily stand-up is a process, a tool, to implement the following principle:

"The most efficient and effective method of conveying information to and within a development team is face-to-face conversation."

And it also contributes to this one:

"The best architectures, requirements, and designs emerge from self-organizing teams."

I believe the daily standup is part of XP (http://www.extremeprogramming.org) which is an Agile Method.