عَنْ عُبَادَةَ بْنِ الصَّامِتِ رَضِيَ اللَّهُ عَنْهُ قَالَ كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ إِذَا رَأَى الْهِلَالَ قَالَ اللَّهُ أَكْبَرُ الْحَمْدُ لِلَّهِ لَا حَوْلَ وَلَا قُوَّةَ إِلَّا بِاللَّهِ اللَّهُمَّ إِنِّي أَسْأَلُكَ خَيْرَ هَذَا الشَّهْرِ وَأَعُوذُ بِكَ مِنْ شَرِّ الْقَدَرِ وَمِنْ سُوءِ الْحَشْرِ
It is narrated from Sayyiduna ‘Ubada bin Samit (may Allah be pleased with him) that when the Messenger of Allah (peace and blessings be upon him) would see the new moon, he would supplicate: Allah is the Greatest, … and from the evil of the gathering (Allah is the Greatest, all praise is for Allah, O Allah! Indeed, I ask You for the good of this month, there is no power to avoid evil and no strength to do good except with Allah’s help, I seek refuge in You from evil destiny and from the evil of the gathering).