قَالَ إِنَّهُ يَقُولُ إِنَّهَا بَقَرَةٌ لَّا ذَلُولٌ تُثِيرُ الْأَرْضَ وَلَا تَسْقِي الْحَرْثَ مُسَلَّمَةٌ لَّا شِيَةَ فِيهَا ۚ قَالُوا الْآنَ جِئْتَ بِالْحَقِّ ۚ فَذَبَحُوهَا وَمَا كَادُوا يَفْعَلُونَ
Qaala innahoo yaqoolu innahaa baqaratul laa zaloolun tuseeral arda wa laa tasqil harsa musallamatun laa shiyata feehaa qaalul aana ji'ta bilhaqq fazabahoohaa wa maa kaadoo yaf'aloon
He said, "God says she is a cow not broken to plow the earth or water the field — sound, with no blemish on her." They said, "Now you have brought the truth." So they slaughtered her, though they nearly did not.
The final specification rules out a working animal, so what is required is a cow that has never been put to use. The episode closes on a clause that undercuts the compliance it reports, saying they nearly did not do it, and commentators have taken that as the point of the whole sequence rather than an aside. The truth is acknowledged only when the description has become narrow enough to be unmistakable.