From either an accrual or cash-flow perspective, it certainly is possible for a single firm to finance growth from its profits. For the economy as a whole, however, it is not financially possible for there to be growth in the aggregate in the absence of credit expansion, into either the B or A circuits, or both.
Credit expansion can derive endogenously or exogenously.
If there is continuous labor displacement in such a purely endogenous regime, debt must compound exponentially in proportion to consumable production.