Share of Profit

I would like to know , in my partnership business why the share of profit is from capital accounts rather than retained earnings?

Under double entry accounting you debit (reduce) Retained Earnings and credit (increase) Share of Profit.

And what about cash ? As the share will be paid in Cash

Cash payments are allocated to Drawings.

So in sharing of profit, cash will not be deducted?

No its only an accounting entry to allocate retained earnings to the partners.