Exodus 4:18 - Matthew Poole's English Annotations on the Holy Bible

He pretends only a visit, and so indeed it was, and that no very long one neither: he knew that he should certainly return to this place, and there meet with his father-in-law. So that he did not deceive him, nor intended to do so though he thought fit to conceal from him the errand upon which God sent him, lest his father or wife should attempt to hinder or discourage him from so difficult and dangerous an enterprise. Moses shows here a rare example, as well of modesty and humility, that such glorious and familiar converse with God, and the high calling to which God had advanced him, did neither make him forget the civility and duty which he owed to his father, nor make him break forth into public and vain-glorious boasting of such a privilege; as also of his piety and prudence, that he avoided all occasions and temptations to disobedience to God's command.