Sahih Muslim 8457
In-book no 1180وَحَدَّثَنَاهُ ابْنُ أَبِي عُمَرَ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ عَبْدِ الصَّمَدِ، عَنْ مَنْصُورٍ، بِإِسْنَادِ هَؤُلاَءِ وَقَالَ " فَلْيَتَحَرَّ الصَّوَابَ " .
This hadith has been narrated by Mansur and he said: " He should aim at correctness."