Pesukim at end of Shmone Esrei

That is the minhag, and it comes from the Mekubolim. There is a problem with saying the Psukim, since minhag Ashkenaz is not to say יהיו לרצון until after אלוקי נצור, and therefore you are not alowed to say anything that is not part of the Teffiloh then. Some say the Psukim after יהיו לרצון for that reason, but the most common Minhag was to say the Psukim before יהיו לרצון.

Michael FRBSH