Earlier quoted context omitted.
if you have $100M and you need a $1M, you'd use your credit line and borrow $1M and pay it back from interests coming from $100M. it's not that different in corp.
That doesn't make any sense. You'll be paying a higher rate of interest on your loan than you're receiving on your cash. You'd be better off taking the $1m directly out of your cash pile.
When you borrow $1M against $100M in cash or assets its generally considered a very low risk loan, meaning you'll likely get good terms and comparatively low rates.