dua that gurantees an answer ..

 

The Arabic supplication you are referring to is one of the most powerful and beautiful invocations in Islam.

 The Prophet Muhammad (ﷺ) referred to it as an invocation that contains Allah's Greatest Name (Ism-e-A'zam)—meaning that if Allah is called upon by this name, He responds, and if He is asked, He gives.

The Arabic Text

اللَّهُمَّ إِنِّي أَسْأَلُكَ بِأَنَّ لَكَ الْحَمْدَ، لَا إِلَهَ إِلَّا أَنْتَ وَحْدَكَ لَا شَرِيكَ لَكَ، الْمَنَّانُ، بَدِيعُ السَّمَوَاتِ وَالْأَرْضِ، يَا ذَا الْجَلَالِ وَالْإِكْرَامِ، 

يَا حَيُّ يَا قَيُّومُ

Transliteration

Allahumma inni as'aluka bi-anna lakal-hamd, la ilaha illa Anta, wahdaka la sharika laka, Al-Mannaan, Badi'us-samawati wal-ard, Ya Dhal-jalali wal-ikram,

 Ya Hayyu Ya Qayyum.

Translation

"O Allah,

 I ask You as all praise is due to You; none has the right to be worshipped but You alone, You have no partner or associate. The Bestower of favors, the Originator of the heavens and the earth, O Possessor of majesty and honor, O Ever-Living, O Sustainer and Protector of all that exists."

📖 Context & Recitation

The Hadith:

 This supplication is famously recorded in several authentic collections, including Sunan Abu Dawud and Sunan an-Nasa'i.

 It was narrated by Anas bin Malik (RA) that the Prophet (ﷺ) heard a man reciting this while praying.

 Upon hearing it, the Prophet (ﷺ) declared that the man had used Allah's Greatest Name to invoke Him.

When to Recite:

 It is a highly recommended and blessed supplication to recite in your prayers (such as after the final Tashahhud, just before making the Salam). 

You can also recite it at any time during your personal supplications (Dua) to praise Allah before asking for your needs.

wallahu a'lam ..