The Muslims have to pray for their brothers in Gaza in the daily prayers and otherwise
Question

                Is it mustahabb to say Qunoot during the daily prayers for our brothers in Gaza, so that Allaah will relieve them of the aggression of the Jews? In which prayer should Qunoot be said?.
Praise be to Allah.
    Yes, the Muslims should pray 
    for their brothers in Gaza, asking Allaah to protect them and save them, and 
    to help them against their enemy, and to defeat the Jews and those who help 
    them. 

    The imam should say the 
    du’aa’ out loud and the people behind him should say Ameen. If a person is 
    offering the obligatory prayer on his own, he should also say Qunoot. 

    It is proven that the Prophet 
    (blessings and peace of Allaah be upon him) said Qunoot at the time of 
    calamity on a number of occasions: 

    1.

    Some of the Arab tribes 
    betrayed 70 of the companions of the Prophet (blessings and peace of Allaah 
    be upon him) and killed them. Anas ibn Maalik (may Allaah be pleased with 
    him) said: News of that reached the Prophet (blessings and peace of Allaah 
    be upon him), and he prayed Qunoot for a month, praying during Fajr prayer 
    against some of the tribes of the Arabs, against Ri’l, Dhakwaan, ‘Usayyah 
    and Bani Lahyaan. Narrated by al-Bukhaari (3064). 

    2.

    It was narrated that Anas ibn 
    Maalik (may Allaah be pleased with him) said: Qunoot was offered in Maghrib 
    and Fajr prayer. Narrated by al-Bukhaari (798). 

    3.

    It was narrated that Ibn 
    ‘Abbaas (may Allaah be pleased with him) said: The Messenger of Allaah 
    (blessings and peace of Allaah be upon him) prayed Qunoot for a month in 
    Zuhr, ‘Asr, Maghrib, ‘Isha’ and Fajr prayer, when he said: Sami’a Allaahu 
    liman hamidah in the last rak’ah, praying against some tribes of Banu 
    Sulaym, and against Ri’l, Dhakwaan and ‘Usayyah, and those who were behind 
    him said Ameen. Narrated by Abu Dawood (1443). Ibn al-Qayyim said: A saheeh 
    hadeeth. Zaad al-Ma’aad, 1/280; classed as hasan by al-Albaani in 
    Saheeh Abi Dawood, 

    A number of things may be 
    learned from these hadeeths, including the following: 

    Firstly: it is prescribed to 
    pray Qunoot at times of calamity. Ibn Taymiyah (may Allaah have mercy on 
    him) said: Qunoot is Sunnah at the time of calamity. This view is that of 
    the fuqaha’ among the muhadditheen. And it is narrated from the Rightly 
    Guided Caliphs. End quote. 

    Majmoo’ al-Fataawa 
    (23/108) 

    Secondly: The Prophet 
    (blessings and peace of Allaah be upon him) said Qunoot at times of calamity 
    in all of the five daily prayers, and he said Qunoot in Fajr and Maghrib 
    prayer, and especially in Fajr. Ibn Taymiyah (may Allaah have mercy on him) 
    said: Most of his Qunoot -- referring to the Prophet (blessings and peace of 
    Allaah be upon him) -- was in Fajr. End quote. 

    Majmoo’ al-Fataawa 
    (22/269). 

    Ibn al-Qayyim (may Allaah 
    have mercy on him) said: The practice of the Prophet (blessings and peace of 
    Allaah be upon him) was to say Qunoot especially at times of calamity, and 
    not to do so at other times. He did not limit it only to Fajr, rather most 
    of his Qunoot was in Fajr because it is prescribed to make that prayer 
    lengthy. End quote. 

    Zaad al-Ma’aad 
    (1/273) 

    Shaykh Ibn ‘Uthaymeen (may 
    Allaah have mercy on him) said: 

    To sum up, saying Qunoot 
    during the obligatory prayers is not prescribed either in Fajr or any other 
    prayer, except when a calamity befalls the Muslims that is deserving of 
    Qunoot, in which case it is prescribed to say Qunoot for every worshipper in 
    Maghrib and Fajr prayer, and if one says Qunoot in all the prayers, there is 
    nothing wrong with that as some of the scholars said. And when this calamity 
    ceases, Qunoot should be stopped. End quote. 

    Majmoo’ Fataawa Ibn 
    ‘Uthaymeen (14/175) 

    We ask Allaah to hasten 
    relief for our brothers in Gaza, and to give them a way out of every 
    difficulty and relief for every distress, and to curse and destroy the Jews 
    and their helpers, and to send punishment upon them, for He is able to do 
    that. 

    And Allaah knows best.