שמות ו:ז פירוש: רמב״ן, ספורנו, אור החיים וטור הארוך

AND I WILL TAKE YOU TO ME FOR A PEOPLE. That is, when you will come to Mount Sinai and you will accept the Torah. There, [at Mount Sinai], it was said, Then ye shall be Mine own treasure.⁴¹Further, 19:5.

ולקחתי אתכם לי לעם, this will occur at the revelation at Mount Sinai.

וידעתם כי אני ה׳ אלוקיכם, "you will know that I י־ה־ו־ה am the Lord your G'd." G'd means that the Israelites will now receive clear evidence which attribute of G'd it is that will set in motion the various steps of the redemption. They will also realise in retrospect that the attribute of Mercy had been predominant in all of G'd's actions.