Hazrat Salih bin Muslim, may Allah have mercy on him, says that if a person divorces his wife and then, during her waiting period (‘iddah), another man marries her, what is the ruling? He replied that Hazrat Umar, may Allah be pleased with him, says that separation will be enforced between the two. And she will begin a new waiting period (‘iddah) from the second husband, and her dowry (mahr) will be given from the public treasury (bait-ul-mal). The second husband can never marry her, and the first husband may send a marriage proposal. Hazrat Ali, may Allah be pleased with him, says that separation will be enforced between her and her husband. She will complete the first waiting period (‘iddah) and then observe a new waiting period from this husband. That man himself will give her dowry (mahr), and both of them may send her a marriage proposal.

19874 - And (Ali) said (1): She is separated (from him) (2) and her first waiting period is completed, and she observes a new waiting period for this one, and the dowry is given to her for what was made lawful of her private part, and both of them become suitors (3).

Hazrat Sha’bi (may Allah have mercy on him) says that if a person marries a woman during her ‘iddah and then separation is enforced between the husband and wife, she will complete a new ‘iddah of three menstrual cycles, and the remaining ‘iddah will be counted from the first menstrual cycle. And Ibrahim (may Allah have mercy on him) says that she will complete the remaining ‘iddah of the first husband, and then complete three new menstrual cycles.

19876 - And Ibrahim said: (1) She completes what remains from the first and then begins three menstrual cycles.

Hazrat Hakam (may Allah have mercy on him) says that separation will be made between the two. The woman will complete the waiting period (iddah) for the first (husband), then the waiting period for the second man's water (i.e., lineage) will begin. She will also receive the dowry (mahr) from the second husband. When the waiting period is completed, if she wishes, she may marry this second man, or if she wishes, she may marry someone else.