Is the revocable divorce valid if the husband divorces his wife with a single pronouncement and both spouses remain silent after another person says it is "revocable"?

A wife is not considered to have been taken back merely by one of those present saying "She has been taken back" while the divorcing husband remains silent. Rather, the taking back is valid if the husband divorced her with one or two pronouncements, and he had consummated the marriage with her. The taking back occurs by his saying: "I have taken back my wife," or "I have kept her," or "I am taking her back," as long as she is within her waiting period ('iddah), meaning before the passing of three menstrual cycles for one who menstruates, or three months for one who does not menstruate, whether she is old or young. It is sunnah to have witnesses to the taking back. However, if it was the third divorce, then there is no taking back thereafter.