I think Dils meant that Saachi trusted DV with giving him her heart and soul when he first proposed to her.
The Diwali night, when after Saachi shared her fears about their age difference.. their social standing.. and everything else ... he asked her to trust him that as long as they are together, they will fight all the odds. Saachi believed him and trusted him then... which was how their relationship began in the first place.After that.. the trust issues between them were due to Saachi's own insecurities - the ups and downs in any relationship.
I guess nothing is concrete abt that dialogue...all r interpreting in their own ways 🤣