1,133. Permitted Signs

166:2 A house, a baby, and a woman are not sorcery but they are a sign. For example, if one built a house, had a baby, or married a woman, whether he succeeds in three subsequent endeavors or not, it is a good indicator for him in the future and he can say such things as 'this house was lucky for me." Similarly, one is permitted to ask a child what verse of Torah he learned and then to rely on this in making some decision, as this is considered a little bit like prophecy. Some authorities permit a person to make a sign of something that will happen in the future, as was done by Avraham's servant Eliezer and King Saul's son Jonathan; other authorities prohibit this. One who lives sincerely and trusts in G-d will be surrounded by G-d's kindness.

166:3 What does it mean to observe times? This means one who predicts that certain days, months or years are good for a given activity, while other days, months or years are bad. The custom of only marrying on the full moon is not considered divination because this is only done as a good sign, like anointing kings in a spring as a sign that their reign will endure. Similarly, the waxing moon is taken as a good sign for the marriage. In any case, one should not delay a wedding because of this, and one certainly shouldn't schedule the wedding for when the woman is menstruating in order to marry at the full moon. There is an accepted practice to start learning on Rosh Chodesh; the practice some have of not starting on Monday or Wednesday is also permitted.