Where is authentication of how much good deeds (sawaab) will be given on an event

Question

One question has always raised in my mind that who decides the amount of good deeds (sawaab) will be given on doing something good, i.e. this is the number of good deeds on every recited word from Qur'an.

Because we are Muslim, we shouldn't just follow something that looks good, we will follow only if their is a reliable authentic source.

I just received a massage from one of my friend.

Their are 1760 words in Azan (call of prayer). Quietly listening to a single word will give us 1500 sawaab (good deeds), that makes total 26,40000 sawaab (good deeds) on listening complete Azan quietly.

Now we don't have any authentic source of above.

Answer 1

The reality as detailed in the Quran is very different. The only manner in which bad deeds can be removed is through doing actual real good deeds and the sum total of all our deeds will be weighed by God Himself for each of us individually in order to determine our eternity.Period." The ten to one ratio and the doubling of good and bad deeds are the only numbers associated with deeds in the Quran."

Allah says: "Whoso bringeth a good deed will receive tenfold the like thereof, while whoso bringeth an ill-deed will be awarded but the like thereof; and they will not be wronged." Quran 6:160

Some of the references for the doubling are: Quran 33:58/38:61/17:75 and multiplication is mentioned in Quran 57:11 confirming Quran 6:160