'Abdullah ibn 'Amr ibn al-'As said, "A liar is someone who lies in his oath. A miser is someone who is miserly with the greeting. A thief is someone who steals the prayer."  

عَنْ عَبْدِ اللهِ بْنِ عَمْرِو بْنِ الْعَاصِ قَالَ الْكَذُوبُ مَنْ كَذَبَ عَلَى يَمِينِهِ وَالْبَخِيلُ مَنْ بَخِلَ بِالسَّلاَمِ وَالسَّرُوقُ مَنْ سَرَقَ الصَّلاةَ  

Abu Hurayra said, "The most miserly of people is the one who is miserly with the greeting. The most incapable of people of people is the one who is the most incapable of supplication."  

عَنْ أَبِي هُرَيْرَةَ قَالَ أَبْخَلُ النَّاسِ الَّذِي يَبْخَلُ بِالسَّلاَمِ وَإِنَّ أَعْجَزَ النَّاسِ مَنْ عَجَزَ بِالدُّعَاءِ