Sanhedrin 107a(1) suggests that Abraham, Isaac, and Jacob were all tested (while David was not). Abraham was tested 10 times, Isaac was tested at the Akedah...But what was Jacob's test? And where do we find this in the midrash (i.e. what is the source of your answer)?
Related to this question:Why was no one else tested 10 times the way Avraham was?
(1) Rab Judah said in Rab's name: One should never [intentionally] bring himself to the test, since David king of Israel did so, and fell. He said unto Him, 'Sovereign of the Universe! Why do we say [in prayer] "The God of Abraham, the God of Isaac, and the God of Jacob," but not the God of David? ' He replied, 'They were tried by me, but thou wast not.'