"Yeshayahu" - (m.); the Prophet Isaiah, considered by CHAZAL as the greatest of the prophets, after Moshe. He prophesied during the reign of the four Judean Kings Uzziah, Yotam, Achaz and Yechizkiyahu and into the beginning of the reign of King Menashe who, according to one opinion (Yevamot 49), killed him.
Yeshayahu did not only foresee punishment for his People, but also a glorious future in the time of the Mashiach, the Messiah. At that time, Yeshayahu prophesies that "the wolf shall dwell with the lamb" (Yeshayahu 11:6). According to the RAMBAN, this is to be taken literally, as referring to an actual change in nature, and reversion to the conditions of Gan Eden. According to the RAMBAM, it is not to be taken exactly literally, but refers to a profound geopolitical change in the world, that will feature the end of war, and the ascendancy of the People of Israel. All the nations will then recognize the Temple in Jerusalem as the spiritual center of the world, and HaShem as the true G-d.
Yeshayahu criticized the People about indulgence in excessive luxury (Yeshayahu 3:16-3:26), the practice of idolatry (Yeshayahu 2:6-10), social injustice (Yeshayahu 5:23), and reliance upon foreign kingdoms for aid rather than trusting in HaShem (Yeshayahu 30:1-5).
He prophesied the destruction of idolatry and the redemption of Israel, "Zion shall be redeemed through Justice, and they that return to her, through mercy" (Yeshayahu 1:27).
And he expressed the classic words of comfort for the Jewish People, "Be comforted, Be comforted, my People" (Yeshayahu 40:1), the beginning of the Haftarah that is read on the Shabbat after Tisha B'Av, Shabbat Nachamu, the Shabbat of Consolation.