It is a verb created from the onomatopoeia "psp", which is used for something that attracts attention, that astonishes, that is fast and surprising. From there it took on meanings as disparate as "to stoke, to warn about" or "to snatch, to steal in an oversight". See pizpireto . Although it may be another interpretation of the previous one, it is also used as "discreetly watching, intuiting", and there is a proposed etymology of the Portuguese bispar ("to observe from afar").
