Rashi on Genesis 26:28/רש"י על בראשית כ״ו:כ״ח

1ראו ראינו WE SAW PLAINLY (literally, seeing we have seen) — We saw it in the case of your father and we see it in the case of yourself (Genesis Rabbah 64:10).

2‘תהי נא אלה בינותינו וגו means LET THE OATH that has existed BETWEEN US since the days of your father CONTINUE NOW BETWEEN US AND YOU.