Q. Why do we say on the Leshem Yichud recitation before counting sefiras haomer, the phrase “kemo shekosuv BaTorah” (as it is written in the Torah), after all in our days the counting is only miderabanan (Rabbinical)

A. Kovetz Halochos (4: 1) indeed mentions that it is better to say “Vekosuv BaTorah” and it is written in the Torah. (See also Piskei Teshuvos 489: n. 48)
Orchois Chaim (489: 4) quotes Meorei Haeish, who asserts that in our times one should also omit; “Lekayem Mitzvas Asseh” I am prepared and ready to perform the positive commandment of counting the omer, since according to most Poskim it is only a Rabbinical mitzva.

Rabbi A. Bartfeld