There is a Benayahu on Taanit 11a I think that may hint to this, but not clear enough. Is there an actual source for "1 hour learning on shabbat is like 1000 hours during the week"?
Ben Ish Chai Shemot Shana Bet, the drasha at the beginning. He states that the action you do in Torah on Shabbat is 1000 times greater than that action during the week.
I have heard that the source of this Ben Ish Chai is a Zohar, however I have as of yet been unable to locate it.
The wording of the Ben Ish Chai is על פי המקובלים, שהלימוד בשבת פועל פי אלף מהלימוד בימות החול