Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
It is proven in the religious texts that saying Astaghfirullah (praying for forgiveness from Allah is a means of having a good life in this world, and a means of being provided with wealth and children , and the means of having rain.
Answering your question, the Fatwa Center at Islam Q and A, states:
It is proven in the religious texts that saying Astaghfirullah (praying for forgiveness from Allah is a means of having a good life in this world, and a means of being provided with wealth and children , and the means of having rain.
We read in the Quran what means:
{[Through a messenger, saying], `Do not worship except Allah. Indeed, I am to you from Him a warner and a bringer of good tidings,’ And [saying], `Seek forgiveness of your Lord and repent to Him, [and] He will let you enjoy a good provision for a specified term and give every doer of favor his favor. But if you turn away, then indeed, I fear for you the punishment of a great Day.’} [Hud 11:2-3]
Shaykh Muhammad Al-Amin Ash-Shinqiti (may Allah have mercy on him) said:
“This verse indicates that praying for forgiveness and repenting to Allah, may He be Exalted, from sin are a means of Allah granting to the one who does that enjoyment of good provision for a specified term, because He has made that the consequences of praying for forgiveness and repenting, as a reward for meeting that condition.
It appears that what is meant by enjoyment of good provision is abundant provision, a life of comfort and well-being in this world, and that what is meant by the specified term is death. This is indicated by what Allah, may He be Exalted, tells us in this Surah about the words of His Prophet Hud (blessings and peace of Allah be upon him):
{And O my people, ask forgiveness of your Lord and then repent to Him. He will send [rain from] the sky upon you in showers and increase you in strength [added] to your strength.} [Hud 11:52]
Allah tells us about Prophet Nuh:
{And said, `Ask forgiveness of your Lord. Indeed, He is ever a Perpetual Forgiver. He will send [rain from] the sky upon you in [continuing] showers, And give you increase in wealth and children and provide for you gardens and provide for you rivers.} [Nuh 71:10-12]
Also Allah says:
{Whoever does righteousness, whether male or female, while he is a believer – We will surely cause him to live a good life…} [An-Nahl 16:97]
{And if only the people of the cities had believed and feared Allah , We would have opened upon them blessings from the heaven and the earth.} [Al-A `raf 7:96]
{And if only they upheld [the law of] the Torah, the Gospel, and what has been revealed to them from their Lord, they would have consumed [provision] from above them and from beneath their feet.} [Al-Ma’idah 5:66]
{And whoever fears Allah – He will make for him a way out, And will provide for him from where he does not expect.} [At-Talaq 66:2-3]
And there are many similar verses.” (Adwa’ Al-Bayan, 3/11-12)
Almighty Allah knows best.
Source: IslamQA.Info