לֵךְ וְאָֽסַפְתָּ אֶת־זִקְנֵי יִשְׂרָאֵל וְאָמַרְתָּ אֲלֵהֶם ה' אֱלֹקי אֲבֹֽתֵיכֶם נִרְאָה אֵלַי אֱלֹקי אַבְרָהָם יִצְחָק וְיַעֲקֹב לֵאמֹר פָּקֹד פָּקַדְתִּי אֶתְכֶם וְאֶת־הֶעָשׂוּי לָכֶם בְּמִצְרָֽיִם׃
“Go and assemble the elders of Israel and say to them: the LORD, the God of your fathers, the God of Abraham, Isaac, and Jacob, has appeared to me and said, ‘I have taken note of you and of what is being done to you in Egypt,
...
And then Hashem tells Moshe (Shemos 3:18):
וְשָׁמְעוּ לְקֹלֶךָ וּבָאתָ אַתָּה וְזִקְנֵי יִשְׂרָאֵל אֶל־מֶלֶךְ מִצְרַיִם...
They will listen to you; then you shall go with the elders of Israel to the king of Egypt ...
After which Moshe says that The Bnei Yisrael will not believe him, and Hashem gives him the signs. Then Moshe still refuses to go to Pharoh, and Hashem tells him to Take Aharon with him.
Then Moshe goes back to Midyan to his wife and children to Mitzraim.
After which Hashem tells Moshe (Shemos 4:21):
וַיֹּאמֶר ה' אֶל־מֹשֶׁה בְּלֶכְתְּךָ לָשׁוּב מִצְרַיְמָה רְאֵה כָּל־הַמֹּֽפְתִים אֲשֶׁר־שַׂמְתִּי בְיָדֶךָ וַעֲשִׂיתָם לִפְנֵי פַרְעֹה ...
And the LORD said to Moses, “When you return to Egypt, see that you perform before Pharaoh all the marvels that I have put within your power...
QUESTION:
Originally Hashem told Moshe to go to to Bnei Yisrael, and then to Pharoh, yet when he is finally ready to go, Hashem only mentions going to Pharoh and does not repeat the part about going first to Bnei Yisrael. WHY?