In the birchot keriat shema of Shabbat morning, we add a number of pesukim in the beginning, and we switch the piyut of קל ברוך גדול דעה for the piyut of קל אדון. But all the pesukim said on a weekday are still said, with the exception of the second: 'מה רבו מעשיך ה. It is said in Nusach Sefard, right after המאיר לארץ. Why is it skipped in Nasuch Ashkenaz?
R' Shalom Dovber of Lubavitch writes that it has to do with the difference between the different modes in which Hashem constantly re-creates the world. On weekdays, this is done by Hashem speaking it into existence, which for Him is a form of action (דיבורו של הקב"ה חשיב מעשה), whereas on Shabbos this is done through Hashem's attribute of Wisdom (chochmah). Based on this logic, then, it is inappropriate to quote the verse speaking of מעשיך, Hashem's actions, on Shabbos.
However, R' Shalom Dovber goes on to say, Nusach Ari retains this verse on Shabbos too, because in truth, chochmah is no closer to G-d's ineffable Essence than speech - both of them are as equally inferior as material action in relation to Him, and indeed this very verse associates chochmah with "doing" (כולם בחכמה עשית). So this verse is suitable for Shabbos as well.