Sahih Muslim Book - 5, Hadith - 1382

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِى شَيْبَةَ وَعَمْرٌو النَّاقِدُ قَالَ عَمْرٌو حَدَّثَنَا سُفْيَانُ عَنِ الزُّهْرِىِّ عَنْ عُرْوَةَ عَنْ عَائِشَةَ كَانَ النَّبِىُّ -صلى الله عليه وسلم- يُصَلِّى الْعَصْرَ وَالشَّمْسُ طَالِعَةٌ فِى حُجْرَتِى لَمْ يَفِئِ الْفَىْءُ بَعْدُ. وَقَالَ أَبُو بَكْرٍ لَمْ يَظْهَرِ الْفَىْءُ بَعْدُ.

It was narrated from 'Aishah that the Prophet (s.a.w) used to pray 'Asr when the sun was shining into her apartment and the afternoon shadow had not yet appeared. Abu Bakr said: "had not yet become manifest."