Halakhah su Isaia 54:11

Beginning with the Shabbos following Tishah beAv and after that, for the next seven Shabbosos we read the haftoras "sheva denechamasa" [seven haftoras of consolation]. If the first day of Rosh Chodesh Elul occurs on Shabbos, the haftorah, Aniyah so'arah, is set aside ["O you afflicted, floundering in the storm,"] (Isaiah 54:11) and we read instead, "Hashamayim kis'i," [The heaven is My throne] (Isaiah 66:1), because this haftorah also contains consolation for Jerusalem. On the Shabbos of Parshas Ki Seitzei, when the haftorah Roni akarah [Sing, O barren woman] (Isaiah 54:1) is read, we conclude the haftorah with Aniyah so'arah, which is next to it. If, by mistake, on Shabbos Rosh Chodesh Elul, you said Aniyah so'arah, and you became aware of it before saying the concluding berachos, you should also say Hashamayim kis'i, and then say the concluding berachah. If you only became aware [of your error] after saying the concluding berachos, then you should recite, Hashamayim kis'i without the berachos. If Rosh Chodesh Elul occurs on Sunday, the haftorah, Machar Chodesh is set aside, [Tomorrow is Rosh Chodesh] (I Samuel 20:18), because it contains no consolation for Jerusalem, and the haftorah Aniyah so'arah is read.

Laws of Rosh Ḥodesh that happens to fall on Shabbat, which has three clauses: On Rosh Ḥodesh that happens to fall on Shabbat, for the 'aravit, shaḥarit, and minḥah services pray the regular seven blessings, but say Ya'aleh v-Yavo in the 'avodah prayer, and it is not necessary to menton Shabbat in the Ya'aleh v-Yavo. And take out two Torah scrolls, and read from the first the seven regular readings for the day, and from the second read the mafṭir — "and on the Sabbath day" and "and on your new moons" until the end of the portion, Numbers 28:9-15. And as a prophetic conclusion read Isaiah 66, "The heavens are My throne" except for Rosh Ḥodesh Elul that falls on Shabbat, on which we read Isaiah 54:11–55:5, "Unhappy, storm-tossed..." (Rema: And some do say Isaiah 66, and thus is the custom in our lands, but on Rosh Ḥodesh Av that falls on Shabbat we as a prophetic conclusion read the portion starting with Jeremiah 2:4, "Hear ye," and this is the general practice where there is no custom. And if Rosh Ḥodesh happens upon one of the four special Shabbatot, we read the final prophetic reading for that reading, and see below, siman 785.)