Does my marital relationship, after I had divorced my wife in writing, then she returned to serve my mother and I said, "So it is," and I had sexual intercourse with her after a period, count as a legitimate relationship, or has the divorce become irrevocable and this relationship is considered adultery, and what must I do?

If a man divorces his wife with a revocable divorce, he may take her back by word or deed with the intention of reconciliation, as long as she is still within her waiting period (iddah (definition)). The waiting period for a menstruating woman is three menstrual cycles, for an old woman (beyond childbearing age) and a young girl (before menstruation) it is three months, and for a pregnant woman it is until she gives birth. Saying "okay" without the intention of reconciliation is not considered a reconciliation. This is indicated by the husband's failure to approach his wife for a year. The subsequent sexual intercourse was an unlawful act and necessitates repentance and the renewal of the marriage contract if they wish to return to each other, subject to its conditions of a guardian, a dowry, and two witnesses.