لَمْ يُوجَدْ فِي رِوَايَتِهِمِ اخْتِلَافٌ شَدِيدٌ وَلَا تَخْلِيطٌ فَاحِشٌ كَمَا قَدْ عُثِرَ فِيهِ عَلَى كَثِيرٍ مِنَ الْمُحَدِّثِينَ وَبَانَ ذَلِكَ فِي حَدِيثِهِمْ
Translation: Their narrations do not exhibit severe divergence or gross confusion of the sort demonstrable in the reports of many transmitters.
Severe divergence means a substantial pattern of conflict affecting accuracy; gross confusion is serious mixing of chains or reports. Al-Nawawī explains that an otherwise precise transmitter may occasionally differ: critical assessment depends on the pattern and weight of the errors, not the mere occurrence of any variation.