Because everything belongs to Him.
So ‘Tera tujhko arpan, kya laage mera’. It becomes the exchange of love. The article you offer that belongs to Krishna, back to Him, Srila Prabhupada says that reciprocation becomes medium of exchange of love between you and Krishna.
Srila Prabhupada gives a very beautiful example of a child and a father. The father bought one pound candy and he gives to his child. It is the father’s money, father’s candy and he gives it to the child. And the child says this is mine, this belongs to me but other child, out of love says -“My dear father, this is a very nice candy, please taste.” He has jaundice or diabetes, he doesn’t want, but my father, please take one.
It belongs to the father. With the candy the mood and love that is involved.
Reciprocation between you and Krishna ,you belong to Krishna, yours belongs to Krishna , everything belongs to Krishna. But if you offer it back to him, then it becomes exchange of love.
“Yat karosi yad asnasi
yaj juhosi dadasi yat
yat tapasyasi kaunteya
tat kurusva mad-arpanam ”
Offer it to Me-
“patram, puspam, phalam, toyam
yo me bhaktya prayacchati”
Bhaktya, out of love. One who gives me out of love, that ingredient love, I accept that.
And if you don’t offer, then what ?
Then Krishna says –
” Yagna-shishtaa-shinah santo muchyante sarva-kilbishaih
Bhunjate te tvagham paapaa ye pachantyaatma-kaaranaat.”
Agham paap, Ghor paap. Invariably, you are eating sins, nothing but sins because you haven’t offered it to Krishna.
“Yagna-shishtaa”, whatever is left over from fire sacrifice, offerings to Krishna. That, if you don’t offer to Krishna, then it becomes ghastly sin and you are eating sin. Your existence, your body will become sinful. No clear consciousness.
One who doesn’t offer food to Krishna, that person is the topmost thief.
Nobody is a higher thief than him, who doesn’t offer it to Krishna.
So why offer it to Krishna? Because it belongs to Krishna and Krishna is demanding , offer it to Me and it is His.
It becomes medium of loving exchange.
We have to offer it to Krishna out of love and devotion. Love and devotion are the ingredients, that’s why we have to offer it to Him.
So if you don’t offer, you are the most exalted thief and you are the ‘Ghor paapi’, most exalted sinner, biggest sinner ever.
It is His but He is asking us, you make that offering to Me and in return I will give you prasadam, mercy, which will purify your whole existence. So that’s why offer it to Krishna, just to reciprocate with Krishna.
So why offer it to Krishna?
It is the exchange of love, we want to show Him love, that’s why we offer His stuff back to Him.