Rabbi wa Rabbukallah
When your eyes fall on the new moon, you must not point to it; rather you should turn yourself towards the kiblah, raise both your hands towards the sky, and address the new moon with the following words:
رَبّي وَرَبّكَ اللّهُ رَبّ العَالَمِينَ.
Your and my Lord is Allah; the Lord of the worlds.
Except that You have pardoned us, forgiven us, and had mercy upon us
Ayyuhal Khalqul Muti
It is recommended, at the sight of the new moon of Ramadhan, to say the supplication number forty-three of the al- Sahifah al-Kamilah al-Sajjadiyyah. Sayyid Ibn Tawus narrated that Imam `Ali ibn al-Husayn Zayn al-Abideen (a.s), once, gazed at the new moon of Ramadhan while he was walking. He therefore stopped and said the following:
أَيّهَا الخَلْقُ المُطِيعُ،
O obedient creature,
speedy and untiring,
المُتَرَدّدُ فِي مَنَازِلِ التّقْدِيرِ،
frequenter of the mansions of determination,
المُتَصَرّفُ فِي فَلَكِ التّدْبِيرِ،
moving about in the sphere of governance!
آمَنْتُ بِمَنْ نَوّرَ بِكَ الظّلَمَ،
I have faith in Him Who lights up darknesses through you,