The Book of Greetings
وَحَدَّثَنَا عَبْدُ بْنُ حُمَيْدٍ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، أَخْبَرَنَا مَعْمَرٌ، عَنِ الزُّهْرِيِّ، عَنْ عُبَيْدِ، اللَّهِ بْنِ عَبْدِ اللَّهِ بْنِ عُتْبَةَ أَنَّ أَبَا هُرَيْرَةَ، قَالَ سَمِعْتُ النَّبِيَّ صلى الله عليه وسلم يَقُولُ " لاَ طِيَرَةَ وَخَيْرُهَا الْفَأْلُ " . قِيلَ يَا رَسُولَ اللَّهِ وَمَا الْفَأْلُ قَالَ " الْكَلِمَةُ الصَّالِحَةُ يَسْمَعُهَا أَحَدُكُمْ " .Abu Huraira reported:I heard Allah's Messenger (ﷺ) as saying: There is no divination but the best type is the good omen. It was said to Allah's Messenger (ﷺ): What is good omen? Thereupon he said: A good word which one of you hears
From Sahih Muslim, whose reports the scholars accept as authentic.