Assalam walekum, i just want to ask what is the dua of Hazrat Daud Alayis Salam which melted iron for him i want to know the full dua and how i can recite this upto how many daya and if moharram comes can i recite it in moharram also or stop at that time plz guide me im very much confused.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

We could not find any text containing a specific Du‘aa' (supplication) that Prophet Daawood (David) would say for Allaah to make iron melt for him. It may be appropriate to mention some of the reported Du‘aa' that Prophet Daawood recited. For instance, Abu Ad-Dardaa’ reported that the Prophet, sallallaahu ‘alayhi wa sallam, said: "One of the supplications recited by Daawood was: 'Allaahumma inni as'aluka hubbaka, wa hubba man yuhibbuka, wa al-‘amal allathi yuballighuni hubbak. Allaahumma-j‘al hubbaka ahabba ilayya min nafsi, wa ahli, wa min al-maa' al-baarid' (O Allaah! I ask You for Your Love, the love of those who love You, and deeds which will cause me to attain Your Love. O Allaah! Make Your Love dearer to me than myself, my family and cool water)." [At-Tirmithi: Hasan (good)]

Ibn ‘Abbaas narrated that Prophet Daawood used to recite the following supplication: "Allaahumma inni a‘oothu bika min maalin yakoonu fitnah, wa min waladin yakoonu ‘alayya wabaalan, wa min imra'ti as-soo' tuqarribu-sh-shayb qabl al-masheeb, wa a‘oothu bika min jaari saw'in tar‘aani ‘aynaahu wa tasma‘ni ‘uthunaahu; in ra'a hasanatan dafanaha, wa in ra'a saiyy'atan athaa‘aha (O Allaah, I seek refuge in You from wealth that is a tribulation, and from a child that causes harm, and from a bad wife who causes me to grow old at a young age, and from an evil neighbor whose eyes see me and whose ears hear me, and who conceals what he sees of good and makes public what he sees of bad.)” [Al-Mu‘jam Al-Awsat by At-Tabaraani]

Sa‘eed ibn Abi Sa‘eed reported that Prophet Daawood used to supplicate saying, "Allaahumma inni a‘oothu bika min jaari as-saw'" (O Allaah, I seek refuge in You from an evil neighbor)." [Al-Musannaf by Ibn Abi Shaybah]

In general, a Muslim is commanded to turn to his Lord in supplication (at all times and in all situations) and implore Him with any given supplication. One of the reported comprehensive supplications was narrated by Nafee‘ ibn Al-Haarith that the Prophet, sallallaahu ‘alayhi wa sallam, said: "The supplications of distress are, 'Allaahumma rahmataka arju, fala takilni ila nafsi tarfata ‘ayn, wa aslih li sha'ni kullahu, la ilaaha illa ant (O Allaah, Your mercy I desire, so do not leave me in charge of my affairs even for the blink of an eye and rectify for me all of my affairs. None has the right to be worshipped except You)." [Abu Daawood and Ahmad]

Ibn ‘Abbaas narrated that the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, used to say when he was in distress: "La ilaaha illa Allaah al-‘Atheem al-Haleem; la ilaaha illa Allaah rabbu-s-samaawaati wa rabbu-l-ardhi wa rabbu-l-‘arshi-l-‘atheem (There is no god (worthy of worship) but Allaah, the Great, the Forbearing; there is no god (worthy of worship) but Allaah, Lord of the heavens, Lord of the earth and Lord of the Great Throne)." [Al-Bukhari and Muslim]

Anas reported that the Prophet, sallallaahu ‘alayhi wa sallam, used to supplicate: “Allaahumma la sahla illa ma ja‘altahu sahlan, wa anta taj‘alu-l-hazna sahlan ithaa shi't (O Allaah, there is no ease except what You make easy, and you alone can make the difficult easy).” [Ibn Hibaan]

The more a Muslim observes the proper conduct of supplication, and the more one pursues the most virtuous times, the more likely it is for one's supplication to be answered. Please refer to Fataawa 83421 and 85023 about the proper conduct of supplication and Fatwa 88296 about the most virtuous times when supplications are likely to be answered.

Allaah Knows best.