Hadithcore
Riyad as-Salihin, 1228

Talhah bin Ubaidullah (May Allah be pleased with him) reported:

At the sight of the new moon (of the lunar month), the Prophet (ﷺ) used to supplicate: "Allahumma ahillahu 'alaina bil-amni wal-iman, was-salamati wal-Islam, Rabbi wa Rabbuk-Allah, Hilalu rushdin wa khairin (O Allah, let this moon appear on us with security and Iman; with safety and Islam. (O moon!) Your Rubb and mine is Allah. May this moon be bringing guidance and good)." <b>[At- Tirmidhi]</b>.

عن طلحة بن عبيد الله رضي الله عنه أن النبي صلى الله عليه وسلم كان إذا رأى الهلال قال‏:‏ ‏

‏اللهم أهله علينا بالأمن والإيمان والسلامة والإسلام، ربي وربك الله، هلال رشد وخير‏

‏ ‏(‏‏(‏رواه الترمذي وقال‏:‏ حديث حسن‏)‏‏)‏‏.‏

References1 variant
In-Book Reference
Book 8, Hadith 238
Sharh · explanationclick to expand
<b>Guidance from the Hadith:</b><br> 1) It is recommended to say this supplication upon sighting the new moon of every (lunar) month.<br> 2) When a person regularly makes the Prophetic supplication for security, faith, safety, and remaining in Islam, he thus combines all desired things and seeks salvation from all feared ones.<br> 3) A person should take pride in being a servant of Allah Almighty, Who is the Lord and Possessor of all things, and He is the One worthy of being worshiped and glorified. Planets, stars, or stones should not be worshiped, for they are created beings, not deities.