[Avodah] who do you ask to explain a pasuk

[Lisa Liel]

On 9/30/2013 3:14 PM, Ben Waxman wrote:
> Rav Yehoshua Reiss, in an article in the book "Hi Sichati"...
> Rav Hai Gaon was learning with his students and they came across a 
> pasuk from Tehillim (141:5). There was a difference of opinion about 
> its meaning. Rav Hai told Rav Mazliach to go to the Catholic 
> (monestary?) and ask him how he explains this verse.

What's his source for this story?