That the Prophet ﷺ entered upon her on Friday while she was fasting. He asked: Did you fast yesterday ? She said: No. He again asked: Do you intend to fast tomorrow ? She said: No. He said: So break your fast. (Using translation from Abū Dāʾūd 2422)
أَنَّ رَسُولَ اللهِ ﷺ دَخَلَ عَلَى جُوَيْرِيَةَ فِي يَوْمِ جُمُعَةٍ وَهِيَ صَائِمَةٌ فَقَالَ لَهَا أَصُمْتِ أَمْسِ؟ قَالَتْ لَا قَالَ تَصُومِينَ غَدًا؟ قَالَتْ لَا قَالَ فَأَفْطِرِي