Siman 483

(40.) Once there were difficulties during a certain month when there was no moon — and it seems they did not sanctify it that month at all. Afterwards Rabbainu o.b.m. said that one must try to begin early to sanctify the moon before seven days. And he commanded to look in the halachic authorities — and we saw that the majority of the decisors agree to sanctify it early — as the law is from the Gemara, as cited in the Turei Zahav and Magen Avraham in paragraph 426. See Mishb'tzos Zahav there. Once I delayed the sanctification of the moon and he commanded me that when I see it through the clouds as it is, I should immediately sanctify it — meaning that I should not be strict about stringencies at all, since when one sees it through the clouds as it is, it is a mitzvah to sanctify it. (Said the transcriber: It is obvious that his intention is to say: through thin and light clouds, according to the law — and see in the Siddur of the Yaabetz.)