So far, it is clear that the Lord God has difficulties communicating with humans. Therefore he has to talk to people who are not necessarily perfect ( whatever this means in his world) but to people that are capable of hearing him. If he thinks that this ability is hereditary, then his promises to increase the number of descendants of such a person make perfect sense, because, looking into the future, if there's no communication/understanding, the chances of uncoerced compliance are very low.