'Planning' in the Bible

Requesting him to do them a favor against Paul, they urged Festus to summon him to Jerusalem, planning an ambush to kill him along the way.

Therefore when I was planning to do this, I did not do so without thinking about what I was doing, did I? Or do I make my plans according to mere human standards so that I would be saying both "Yes, yes" and "No, no" at the same time?