The word(s) "alternate" appears 2 time(s) in 2 verse(s) in Quran in Saheeh International translation.

(1) If a wound should touch you - there has already touched the [opposing] people a wound similar to it. And these days [of varying conditions] We alternate among the people so that Allah may make evident those who believe and [may] take to Himself from among you martyrs - and Allah does not like the wrongdoers -

(2) Allah alternates the night and the day. Indeed in that is a lesson for those who have vision.