'rewrite' doesn't want to match large expression

I have a proven lemma which goes something along the lines of:

Lemma my_lemma : forall (x y : some_type), Foo x y = expression .
actual proof

And I want to use it in a goal that contains:

Foo (large_expression1) (large_expression2)

However, rewrite * -> my_lemma doesn’t seem to identify that particular occurrence. To further complicate things, expression, large_expression1 and large_expression2 all contain occurrences of the pattern.

Is there any way I could rewrite those without explicitly passing them to replace and then proving the equality? Those large expressions are really large.

Well, turns out ‘rewrite’ was perfectly fine. One of the inner expressions contained a term from a forall at the top level, when I expected the opposite. Using ‘intros’ fixed the problem, but now I’ll need to rethink my proof…