Rashi on Exodus 6:6/רש"י על שמות ו׳:ו׳

1לכן THEREFORE, i. e. in accordance with the tenor of that oath (cf. Exodus Rabbah 6)

2אמר לבני ישראל אני ה׳ SAY UNTO THE CHILDREN OF ISRAEL, I AM THE LORD Who am faithful in My promise,

3והוצאתי אתכם AND I WILL BRING YOU OUT, — for so did I promise them: (Genesis 15:14) “and afterwards shall they go out with great substance”.

4סבלת מצרים means the encumbrance of the burdens of Egypt.