Sahih Muslim 8455
In-book no 1178حَدَّثَنَاهُ مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، حَدَّثَنَا شُعْبَةُ، عَنْ مَنْصُورٍ، بِهَذَا الإِسْنَادِ وَقَالَ " فَلْيَتَحَرَّ أَقْرَبَ ذَلِكَ إِلَى الصَّوَابِ " .
This hadith has been narrated by Mansur with the same chain of transmitters and said: " He should aim at correctness and that is right."