DUA 18

18. Supplicate without a sin or breaking blood ties.
Ahmad records that Abu Sa’id reported that the Prophet, peace be uponhim, said, “Any Muslim who makes a supplication containing nothingthat is sinful and nothing that involves breaking ties of bloodrelationships, will be given for it by Allah one of these three things: Hemay accept his request, or assign its reward for him in the next world,or turn away from him an equivalent amount of evil.” Those who heardit said, “We would, then, make many supplications.” The Prophet, peacebe upon him, replied, “Allah is more than ready to answer what youask.”Source:

Fiqh-us-Sunnah, volume 4: 11219. End your supplication (dua) with amin.We went out with the Apostle of Allah (peace be upon him) one night and came upon a man who made supplication with persistence. The Prophet (peace be upon him) waited to hear him. The Prophet (peace be upon him) said: He will have done something which guarantees (Paradise for him) if he puts a seal to it. One of the people asked: What should he use as a seal? He replied: Amin, for if he ends it with Amin, he will do something which guarantees (Paradise for him).Source: Narrated by AbuZuhayr an-Numayri in Sunan Abu Dawood, hadith #361