Wife as Mashgiach

Netziv (Bereishis 4:19) We have already explained  regarding the wife being an Ezer Kenegdo that there are two aspects 1) To be available to fulfill all the husbands's wishes and desires even though they might be mistaken or unhelpful and thus by fully complying with his requests she is actually impeding him 2) she is controlling  and opposes his harmful desires and thus she ends up helping him. Lemech picked two wives for these two goals. The first wife was Aidah who blocked his attemot to do foolish things. The second was Tzila who agreed and encourage everything he wanted. Similarly Dovid had two wives Avigail and Michal. Avigail was for this world while Michal was concerned about the next In other words Avigail kept him frim sinning