Sahih al-Bukhari, Hadith 7178 ⓘ
Narrated Muhammad bin Zaid bin `Abdullah bin `Umar: Some people said to Ibn `Umar, "When we enter upon our ruler(s) we say in their praise what is contrary to what we say when we leave them." Ibn `Umar said, "We used to consider this as hypocrisy."
حَدَّثَنَا أَبُو نُعَيْمٍ، حَدَّثَنَا عَاصِمُ بْنُ مُحَمَّدِ بْنِ زَيْدِ بْنِ عَبْدِ اللَّهِ بْنِ عُمَرَ، عَنْ أَبِيهِ، قَالَ أُنَاسٌ لاِبْنِ عُمَرَ إِنَّا نَدْخُلُ عَلَى سُلْطَانِنَا فَنَقُولُ لَهُمْ خِلاَفَ مَا نَتَكَلَّمُ إِذَا خَرَجْنَا مِنْ عِنْدِهِمْ قَالَ كُنَّا نَعُدُّهَا نِفَاقًا.
also referenced under: Book 93, Hadith 41 (In-Book) & Volume 9, Book 89, Hadith 289 (USC-MSA)