Hindus: Why a "Receiver of Dhaanam" should perform Gayatri japa for certain times?

Hinduism has the concept of punyam and Paapam. It's like have a savings account (for punya) and a debt account (for Paapam). Every time we do a good deed, our savings account gets credited with punya. Every time we do a bad deed, our outstanding debt (paapam) increases in the debt account. The merrier and happier we are, means we are exhusting our savings account. The more sad and sufferings we go thro, the more debt we are repaying. Now, going a level further, if we do a good deed/ favor to someone else, some units of punya is debited from their account and is credited to our account as he is enjoying the benefits of our favor. The same case, if we do bad deed to someone else, some units of Paapam (debt) gets transferred from their account to our account as he suffers because of our bad deed. So for your question, the receiver of dhanam is enjoying th benefits of it and some units of punya gets transferred from his account to the account of donor. To replenish his punya account, he should perform gayathri Japam. As simple as that.

Now to your question on Kanya dhanam, we don't have to do anything special. After marriage, our savings (punya) account becomes a joint account. The debt account continue to remain in our name. What this means is, for all the good deed we do, 50% of the credit goes to our wife. But all debt from our bad deed stay with us. What more we need to do? on a lighter note, probably we should start doing all good deeds twice ;-)

Rishishs like Vasista discourage practices like Japa, Tapa, Theertha, Dhaana, etc.

"Kaalam Yajna Tapo dhaana Theertha Devarchanaa Bramaih,

Chiram Aadi shatopeetha Kshapayanthi Mrigaa iva".

(See, Vashista compared such people to animals)

'Kany dhaanam' is the greatest foolish custom followed by Hindu-Brahmins. If they didn't stop selling their daughters like a cow in marriages, Brahmin community will continue in darkness.

The "Receiver" is the Groom only.

The Groom' s parents " Vouch Safe" the Groom' promise.

The Groom is doing "Prayas Chittam" for the rest of his life.!!!!

No one

You may find some information here:

https://www.trsiyengar.com/id63.shtml - India

I don't know if this helps :/