Hadith on Importance of Moon sighting
‘Abdullah ibn ‘Umar RadhiAllahu ‘anhu narrated that the Prophet Muhammad Sallallaho Alaehe Wassallam said, “Do not fast till you have sighted it (the new moon) and do not break it till you have sighted it, except when the sky is cloudy for you, and if it is so, then calculate it.” [Bukhari, Muslim]
Dua For Sighting the New Moon
اللَّهُمَّ أَهِلَّهُ عَلَيْنَا بِالْيُمْنِ وَالْإِيمَانِ وَالسَّلَامَةِ وَالْإِسْلَامِ
وَالتَّوْفِيقِ لِمَا تُحِبُّ وَتَرْضَى رَبِّي وَرَبُّكَ اللَّهُ
“O Allah, let this moon (month) pass over us with blessings, Iman, safety, and in the belief of Islam. Grant us the ability to act on the actions that You love and Pleases You. (O moon) My Lord and Your Lord is Allah”.