Sincerity

the prophet, may allah exalt his mention, was sincere and honest in all his matters, as allah had ordered him. allah, the exalted, said:

(say, 'indeed, my prayer, my rites of sacrifice, my living and my dying are for allah, rubb of the worlds. no partner has he. and this i have been commanded, and i am the first (among you) of the muslims.)  [6:162-163]