Muwatta Malik 1219
موطأ مالك#1219SahihThese are the words of a Successor — the generation after the Companions — not of the Prophet ﷺ.
وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ سَمِعَ ابْنَ شِهَابٍ، يَقُولُ عِدَّةُ الْمُطَلَّقَةِ الأَقْرَاءُ وَإِنْ تَبَاعَدَتْ .
Yahya related to me from Malik that he heard Ibn Shihab say, "The idda of the divorced woman is reckoned by the menstrual cycles even if she is estranged ." (The reason the idda is normally reckoned by the menstrual cycle is to see whether the woman is pregnant or not)
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 29:16