(43) General Behavior (Kitab Al-Adab)
كتاب الأدب
(111) Chapter: What a man should say when he sees the new crescent
(111) باب مَا يَقُولُ الرَّجُلُ إِذَا رَأَى الْهِلاَلَ
Sunan Abi Dawud 5092 

Narrated Qatadah:

When the Prophet of Allah (ﷺ) 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 ‏"‏ ‏.‏
Grade :  Da'if in chain (Al-Albani) ضعيف الإسناد  (الألباني)حكم :
Reference : Sunan Abi Dawud 5092
In-book reference : Book 43, Hadith 320
English translation : Book 42, Hadith 5073