Likutei Sichos Vol. 10 page 49 ff.

Avrorhom’s life divided into two: before and after the Bris. Before he was doing Judaism (like a brick) afterwards he was Jew, a representative of God on this earth (like a stone which is natural and not like a brick which is artificial).

Likutei Sichos vol. 10 page 129 ff.

Yosef knows by process of elimination that he best not tell his father he is alive even once appointed Vizier. He figures out that God is in on it, and He will give the signal when is the time to disclose this information to Ya’akov.

Likutei Sichos vol. 10 page 160 ff.

Yaakov’s best years were in Egypt not because of what was going on with him, but what was going on with his children, who were susceptible to the realities of Golus. Their learning Torah made Yaakov’s stay in Egypt the best moment of His life, as darkness itself was transformed to light.