Lukas 14:28-30

For who among you, wanting to build a migdal (tower), will not first sit down and rechen (calculate) the cost, to see if he has enough to complete it? Otherwise, having laid his yesod (foundation) and not being able to finish it, everyone seeing it may begin to make leitzonus (fun, mockery) of him, Saying, This man began to build and was not able to finish.