Sahih Bukhari
Judgments (Ahkaam)
Volume: 009 / Book Number: 089 / Hadith Number: 289
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."