כה תאמר לבית יעקב ותגיד לבני ישראל
Chazal (Mechilta) teaches that amirah/somar/say implies a mild form of speech, while hagadah/sagid/speak/relate, implies firmness or even harshness of speech. When Moshe Rabbeinu spoke with the women (Bais Yaakov), he expressed the commandments in a manner that was compatible with their compassionate, maternal nature. When speaking with the men (Bnei Yisrael), the tone changed, because the mitzvos had to be transmitted to them with firmness. While this may be true, it is surprising that pasuk 6 concludes with the following words, “These are the words that you shall speak (tidaber) to Bnei Yisrael.” Rashi adds – lo pachos v’lo yoseir…