From chashab (H2803, to think, plan, devise), machashabah means the inward thought life — particularly purposeful planning and scheming, whether evil or good. It covers the full range from artistic design (Bezalel's skilled craftsmanship) to wicked plots to God's eternal purposes.
The contrast between God's machashaboth and human ones is a major prophetic theme. Isaiah 55:8-9 is the climax: 'My thoughts are not your thoughts... my thoughts are higher than your thoughts.' Human plans fail; God's plans stand forever (Ps 33:10-11). Proverbs warns that 'the thoughts of the wicked are abomination' while 'the thoughts of the righteous are just' (Prov 15:26).