Sahih Muslim 1276
The Book of Mosques and Places of Prayer
وَحَدَّثَنَاهُ عَبْدُ اللَّهِ بْنُ عَبْدِ الرَّحْمَنِ الدَّارِمِيُّ، أَخْبَرَنَا يَحْيَى بْنُ حَسَّانَ، حَدَّثَنَا وُهَيْبُ بْنُ خَالِدٍ، حَدَّثَنَا مَنْصُورٌ، بِهَذَا الإِسْنَادِ وَقَالَ مَنْصُورٌ " فَلْيَنْظُرْ أَحْرَى ذَلِكَ لِلصَّوَابِ " .
This hadith is reported by Mansur with the same chain of transmitters, but with these words:" He should aim at correct (prayer) and it is advisable
Text from the public-domain hadith-api dataset. Numbering follows that dataset and can differ by a few from some printed editions — check the wording, not only the number.