Sunan Abi Dawud, Hadith 5073 ⓘ
Narrated Qatadah: When the Prophet of Allah saw the new moon, he said: "a new moon of good and right guidance; a new moon of good and right guidance; a new moon of good and right guidance. I believe in Him Who created you" three times. He would then say: "Praise be to Allah Who has made such and such a month to pass and has brought such and such a month."
حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، حَدَّثَنَا أَبَانُ، حَدَّثَنَا قَتَادَةُ، أَنَّهُ بَلَغَهُ أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ إِذَا رَأَى الْهِلاَلَ قَالَ " هِلاَلُ خَيْرٍ وَرُشْدٍ هِلاَلُ خَيْرٍ وَرُشْدٍ هِلاَلُ خَيْرٍ وَرُشْدٍ آمَنْتُ بِالَّذِي خَلَقَكَ " . ثَلاَثَ مَرَّاتٍ . ثُمَّ يَقُولُ " الْحَمْدُ لِلَّهِ الَّذِي ذَهَبَ بِشَهْرِ كَذَا وَجَاءَ بِشَهْرِ كَذَا " .
also referenced under: Hadith 5092 (DarusSalam) & Book 41, Hadith 5073 (USC-MSA)