שִׁמְע֥וּ דְבַר־יְהוָ֖ה בֵּ֣ית יַעֲקֹ֑ב וְכָֽל־מִשְׁפְּח֖וֹת בֵּ֥ית יִשְׂרָאֵֽל׃
Écoutez la parole de l’Éternel, maison de Jacob, et vous toutes, familles de la maison d’Israël!
Kitzur Shulchan Arukh
On the three Shabbosos between the seventeenth of Tammuz and Tishah beAv, we read the "Three haftaros of retribution," which are: Divrei Yirmiyahu (The words of Jeremiah) (Jeremiah 1:1), Shim'u devar Hashem, (Hear the word of Hashem) (Jeremiah 2:4), Chazon Yeshayahu, (The vision of Isaiah) (Isaiah 1:1). Their initials form the acronym DeShaCh. If, by mistake, the reader recited on the first Shabbos the haftarah of the weekly portion, on the second Shabbos, he should read the haftarah of both Divrei Yirmiyahu and Shim'u, because they are close to each other. If Rosh Chodesh Av occurs on Shabbos, he reads the haftarah Hashamayim Kis'i (The heaven is My throne) (Isaiah 66), but in some communities, the haftarah Shim'u is read.
Shulchan Arukh, Orach Chayim
Laws of Rosh Ḥodesh that falls on Shabbat, which has three clauses:
When Rosh Ḥodesh falls on Shabbat, for the Maariv, Shacharit and Mincha services pray the regular seven blessings, but say Ya'aleh v-Yavo in the avodah prayer, and it is not necessary to menton Shabbat 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, the Maftir reads from “Uviyom HaShabbat uv’Roshei Chodsheichem” until the end of the section. (Numbers 28:9-15). The haftarah is "The heavens are My throne" (Isaiah 66), (and if one mentions Rosh Chodesh there, see Siman 284:2), 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 Hashamayim Kisi (Isaiah 66), (Tur, Mordechai in Perek Bnei HaIr, and the Minhagim) and this is the custom in our lands. However when Rosh Ḥodesh Av falls on Shabbat some say the haftarah is "Hear ye," (Jeremiah 2:4-28) (Avudraham and Mordechai Perek Bnei HaIr and Minhagim) while others still say "Hashamayim Kisi" (Isaiah 66) and this is the general practice where there is no custom (Terumat HaDeshen Siman 19 and the customs of Maharak). 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.
When Rosh Ḥodesh falls on Shabbat, for the Maariv, Shacharit and Mincha services pray the regular seven blessings, but say Ya'aleh v-Yavo in the avodah prayer, and it is not necessary to menton Shabbat 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, the Maftir reads from “Uviyom HaShabbat uv’Roshei Chodsheichem” until the end of the section. (Numbers 28:9-15). The haftarah is "The heavens are My throne" (Isaiah 66), (and if one mentions Rosh Chodesh there, see Siman 284:2), 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 Hashamayim Kisi (Isaiah 66), (Tur, Mordechai in Perek Bnei HaIr, and the Minhagim) and this is the custom in our lands. However when Rosh Ḥodesh Av falls on Shabbat some say the haftarah is "Hear ye," (Jeremiah 2:4-28) (Avudraham and Mordechai Perek Bnei HaIr and Minhagim) while others still say "Hashamayim Kisi" (Isaiah 66) and this is the general practice where there is no custom (Terumat HaDeshen Siman 19 and the customs of Maharak). 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.