Abu Huraira told of hearing God's messenger say, “There should be no taking of omens, but the best type is the good omen." He was asked what a good omen was and replied, “A good word which one of you hears." (Bukhari and Muslim.)

عَنْ أَبِي هُرَيْرَةَ قَالَ: سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ: «لَا طِيَرَةَ وَخَيْرُهَا الْفَأْلُ» قَالُوا: وَمَا الْفَأْلُ؟ قَالَ: «الْكَلِمَةُ الصَّالِحَة يسْمعهَا أحدكُم»