Prov.16:5: “Everyone proud in heart is an abomination to the Lord; Though they join forces, none will go unpunished”.
The first verse gives the clue. “The preparations”, are the thinkings of mankind, which with the natural fallen nature, leads mostly to, ‘not good actions’! See the world’s wars, which have been going on for millennia! See the actions of mankind all the time! These are under the control most of the time of Satan!
The “proud” heart is a product of the enemy, Satan!
The very opposite is seen in Psm. 51:17; “The sacrifices of God are a broken spirit, a broken and a contrite heart- These O God, You will not despise”!
To summarise; V1 of Prov.16 gives the conclusion; “The preparations of the heart belongs to man. But the answer of the tongue is from the Lord”!
For mankind to move towards that lofty premise, is life's work; in the full knowledge that Christ Jesus has the victory in His death and resurrection!