Q. How come we recite the half pasuk “Al Pi Hashem Beyad Moshe,” (that is the way most people say, and the way it is printed in the Artscroll sidurim) during hagbaha. Is that not only half of the pasuk, that one is not supposed to say?

A. The verse “Al Pi Hashem Beyad Moshe,” is indeed the last part of a pasuk in Bamidbar (9: 23) that also begins with “Al pi Hashem,” and not the continuation of the pasuk “Vezos Hatorah” (Devarim 4: 44) now being recited.
Likutei Mhariach and Aruch Hashulchan (134: 2) question why we only recite part of the posuk, since we have a rule that we do not shorten any posuk that Moshe did not shorten. (Megila 22a). Therefore, some sidurim following the Vilner Gaon and the Valoshener tradition present the full verse. (See also Sharei Rachamim, H. Shabbos n. 55). Siach Tefila (p. 244) also asserts that one should recite the two complete verses.
Orchois Rabbenu (1: p. 72) quoting the Steipler Gaon and others maintain that according to the need, we do find partial pesukim being said. (See Piskei Teshuvos 134: 8).
Horav Shlomo Miller’s Shlit’a opinion is that we find sometimes tefilos. statements or a passages in the sidur that were construed from different sections of psukim and thus became accepted.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a