We find several sayings of the Sages regarding dreams. Some sources indicate that one should be concerned about a bad dream and therefore one should fast in order to counteract the harsh decrees. Other teachings convey that there is nothing real about dreams and that they neither help nor hinder. The general rule is that it is better to not worry about dreams and to not fear them at all so that one’s mazal is not weakened. For the same reason, one should not tell others what one dreamed, for in the overwhelming majority of cases “dreams speak lies” (cf. Zechariah 10:2). This is particularly true in an orphaned generation such as ours — no such person can be found whose soul can ascend to the Academy on High and who will be told of future events, nor is there anyone who will be foretold the future through an angel. Our dreams are all just the stuff of imagination that acts without conscience intellect, and it conjures all sorts of scattered thoughts. There are some frightening dreams that come about after excessive eating and drinking or as a result of depression etc. It is therefore better to pay no heed to one’s dreams.
Yet one should be slightly concerned that perhaps Heaven wished to have mercy on the person and inform him of an impending decree that was directed towards him so that he can pay attention and redeem his soul. Therefore, when one dreams a bad dream, he should know that he should not be afraid, for dreams have no effect, and they are but fleeting vexation; but, at the same time, there is no loss in fasting the next day. And if the person has the ability, he should distribute money for tzedakah while giving thought to repenting from whatever misdeeds he may have committed. After all, this is a good and necessary thing to do every day and at all times.