Dire - Imparfait

Hi A,

It is because of the indirect speech created by 'a dit que' -

Take a look at my answer to a similar question which will give you a brief resumé of the rules -

https://kwiziq.learnfrenchwithalexa.com/questions/view/imperfect-and-passe-compose-in-mamie-gateau-lesson

Hope this helps!