The rationale for its legitimacy
a. It emphasizes the seriousness and significance of marriage contracts, highlighting their status and position in Islam
b. It honours the right of the husband after his passing to keep a gap and a time interval between him and the future husband.
c. It is a precautionary measure to preserve the rights of the husband, fulfil the right of Allah, which He has dictated, preserve the rights of the child, and serve the best interests of the wife. It gives the husband room to reconsider his decision and return to his wife during the waiting period, and it allows the woman to fulfil Allah’s right upon her, which is to stay in the house of her husband during the waiting period, and it preserves the right of children by protecting the lineage since the waiting period is enough to determine pregnancy, and thus the father can be easily identified. It protects the right of the wife to alimony during the waiting period; thus, she can inherit the husband if he dies during her waiting period, and the husband can inherit her if she dies during the waiting period.
d. It gives enough time to ensure the wife is pregnant so that the sperm of two men do not be present at the same time inside the woman, lest lineages become mixed, which will lead to corruption that Islam and intellectualism forbid.

2. The causes of the waiting period
The scholars are in consensus that the waiting period for a woman occurs due to divorce or the passing of the husband. This consensus has been transmitted by al-Shafi’i, Al-Jassaas, and Ibn Rushd.