‘Azl (coitus interruptus) and using birth control pills
Question

                according to Jabir radiyaahu canhu said: "we use to do cazli while Quran is revealing and Prophet did not prohibit? my question is as follows

1- Is it allowed to use a condom/pill?

2- if so what is the conditions? 

3- what type of niyyah do we need to have at performing either or both"Condom/Pills/cazli? 

4- Why the Companion doing this?
Praise be to Allah.
    Firstly, what the Muslims should do is to try to have as many 
    children as they can, because this is the command of the Prophet  (peace 
    and blessings of Allaah be upon him), who said: “Marry the one who is loving 
    and fertile, for I will be proud of your great numbers before the nations.” 
    (Narrated by Abu Dawood, 2050; classed as saheeh by al-Albaani in Saheeh 
    Abi Dawood, 1805). 

    Having more children increases the numbers of the ummah, and 
    increasing the numbers of the ummah is a source of its glory, as Allaah 
    says, reminding the Children of Israel of His blessings: 

    “and made you more numerous in man-power”

    [al-Isra’ 15:6 – interpretation of the meaning]

    And Shu’ayb said to his people: 

    “And remember when you were but few, and He multiplied 
    you”

    [al-A’raaf 7:86 – interpretation of the meaning]

    No one can deny that having a large number is a source of 
    pride and strength for the ummah, contrary to what those pessimists think 
    who say that large numbers causes poverty and starvation in a nation. 

    If the ummah increases in number, puts its trust in Allaah 
    and believes His promises as mentioned in the aayah,  

    “And no moving (living) creature is there on earth but its 
    provision is due from Allaah”

    [Hood 11:6 – interpretation of the meaning], 
    then Allaah will make things easy for them and will grant them independence 
    of means from His bounty. Based on that, the answer to your question is as 
    follows: 

    Birth control pills: 

    A woman should not use birth control pills, unless the 
    following conditions are met: 

    1-She should need to use them, 
    for example if she is ill and cannot cope with a pregnancy every year, or 
    she is physically unfit, or there is some other reason that getting pregnant 
    every year may harm her.

    2-Her husband should give his 
    permission, because the husband has the right to have children. There must 
    also be consultation with the doctor, to find out whether these pills are 
    harmful or not. 

    If these two conditions are met, there is nothing wrong with 
    taking these pills, but that should not be on a permanent basis, because 
    that means preventing having children. 

     With regard to ‘azl (coitus interruptus), or withdrawing 
    during intercourse, the correct scholarly view is that there is nothing 
    wrong with it, because of the hadeeth of Jaabir (may Allaah be pleased with 
    him): “We used to practise ‘azl at the time when the Qur’aan was being 
    revealed” – i.e., at the time of the Prophet  (peace and blessings of 
    Allaah be upon him). If that action had been haraam, the Prophet  (peace 
    and blessings of Allaah be upon him) would have forbidden it. But the 
    scholars say that one should not engage in ‘azl with a free woman except 
    with her permission, because she has the right to have children. Moreover, 
    withdrawing without her permission diminishes her pleasure, because the 
    woman’s pleasure can only be completed after ejaculation. So not asking her 
    permission causes her to lose out on pleasure and on the possibility of 
    having children. Hence we state the condition that this may only be done 
    with her permission.

     From Fataawa al-Shaykh Muhammad ibn ‘Uthaymeen.

     From Fataawa Islamiyyah, vol. 3, p. 190.

     Thirdly: the reason why the Sahaabah engaged in ‘azl was 
    because they did not want the woman – especially a slave woman – to get 
    pregnant, so that they could continue to enjoy a physical relationship with 
    them and the woman would still be able to do their work. Abu Dawood narrated 
    that a man said, “O Messenger of Allaah, I have a slave woman and I engage 
    in ‘azl with her, because I do not want her to get pregnant, but I want what 
    men want. But the Jews say that ‘azl is a lesser form of infanticide.” He 
    said, “The Jews are lying. If Allaah wants to create (a child) you cannot 
    prevent that.” (Narrated by Abu Dawood, Kitaab al-Nikaah, 1856; 
    classed as saheeh by al-Albaani in Saheeh Abi Dawood, 1903).