[On Contraceptive Treatment]

Answer: There is no doubt nor suspicion that the Wise Legislator has encouraged marriage and desired abundant offspring.
There is no disagreement among Muslims that marriage is not obligatory solely for procreation, nor is it obligatory for a Muslim to deliberately cause offspring.
There is also no disagreement that a Muslim should not marry unless he fears falling into harm.
The encouragement of marriage and abundant progeny does not indicate the prohibition of using contraceptive treatment; rather, it indicates the priority of avoiding it, which is considered disliked (makruh).
What indicates the permissibility of using contraceptive treatment are the following:
1. The default ruling is permissibility, and the burden of proof is on those claiming prohibition.
2. It has been authentically narrated that the Companions used coitus interruptus (‘azl) during the time of the Prophet Muhammad (May Allah bless him and his family and grant them peace).
As for slaves, there is agreement and consensus on the permissibility. Regarding free wives, the correct view is permissibility, due to the authentic narration that the Companions practiced ‘azl during the time of the Prophet Muhammad (May Allah bless him and his family and grant them peace). This was also the view of Imam Ali (Peace be Upon Him), who responded to those among the Companions who said that ‘azl constitutes minor infanticide, stating its meaning: "It is not considered infanticide until seven menstrual cycles have passed," and the seven menstrual cycles are mentioned in Surat Al-Mu’minun.

Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.3