Search within block property value

I have a number of blocks with properties. These blocks look something like this
source:: ABC
description:: DEF

I would like to query for all blocks with source == ABC that contain E in the description.

How do I do this? I figured out how to search for all source == ABC but I can’t figure out the E part.

Here is what I have:

#+BEGIN_QUERY
{:title [:h2 “Title”]
:query [:find (pull ?b [*])
:where
[?b :block/properties ?p]
[(get ?p :source) ?t]
[(= “ABC” ?t)]]
}
#+END_QUERY

Tammo