Shaan describes leaning, resting or relying, with the support identified by the sentence. Abraham invites visitors to rest beneath a tree, and Numbers uses the verb in a geographical description of slopes along Moab's border. Those ordinary uses should remain ordinary. Proverbs calls for wholehearted trust in the Lord rather than making one's own understanding the final support.
Isaiah invites the person walking in darkness to lean on God, while Chronicles contrasts Asa's earlier reliance on the Lord with later dependence on a political ally. Micah exposes leaders who lean on the Lord in their own claim of immunity even as they judge for bribes and serve for money. The verb therefore can name faithful dependence, physical support or a false religious assurance.
Responsible teaching asks who or what bears the weight and whether that reliance accords with truth and justice. It neither condemns thoughtful reasoning and practical help nor makes a leader's claim to trust God proof of safety.