Does supplication avert the divine decree?

Question:
It was said: It is claimed that supplication and divine decree contend with one another, and that supplication may avert some of the decree or the affliction, just as kindness to parents brings a blessing to the servant in his lifespan. We ask for clarification of the governing principle.

Answer:
It came in a hadith of Thawban, from the Prophet (peace and blessings be upon him), that he said: “Indeed, the servant is deprived of provision by the sin he commits, and indeed, nothing averts the decree except supplication, and indeed, supplication and the decree contend with one another until the Day of Resurrection, and indeed, righteousness increases the lifespan—meaning righteousness to the parents. So supplication is a decree, and the inevitable decree is likewise. Allah may decree things and avert them by other things; He decrees things and averts them by supplication, by charity, and by righteous deeds, and He makes these a means of averting them by His power (Glorified and Exalted is He) .”
So the decree is dealt with by the decree. The decree and supplication contend with one another. It is like when you are grazing sheep or camels; you may graze them in good land—and this is by Allah’s decree—and you are doing well. Or you may graze them in bad, barren land—and this is by Allah’s decree—and you are doing poorly in your work. So it is obligatory for you to seek out the good and to avoid the bad, and all of it is by the decree.
Just as 'Umar said to the people when the plague descended upon Sham and the Muslims were there, and 'Umar resolved to return with the people and not enter Sham—when the plague struck it—some of the people said: “Are we fleeing from the decree of Allah?” He said: “We flee from the decree of Allah to the decree of Allah.” Meaning, our remaining in Sham is a decree, and our returning is a decree; all of it is by Allah’s decree. So we flee from the decree of Allah to the decree of Allah. And just as you flee from the evil to repentance to Allah (Glorified and Exalted is He) , you flee from the disease to treatment by taking injections, or pills, or other medicines. All of it is fleeing from the decree of Allah to the decree of Allah.
Then 'Umar gave an example to the people, saying: “What do you say if a man had camels or sheep, and he grazed them in a fertile meadow? Is that not by the decree of Allah? And he is to be commended for this. But if he grazed them, or took them, to a barren, drought-stricken land, or a land devoid of water and grass, he would be doing poorly—and that is by the decree of Allah.”

So the conclusion : The point is that a person follows what is in the truth, and that is by the decree, and he leaves what is in falsehood, and that is by the decree. All of it is by Allah’s decree. We flee from the decree of Allah to the decree of Allah. If a person disobeys, he has fallen into the disobedience, and the hudud (fixed Qur'anic punishments) that Allah has legislated which are carried out against him are also by the decree. So carrying out the hudud is by the decree, and the sins he committed are by the decree, and his lawful earnings are by the decree, and his unlawful earnings are by the decree. But he is commanded to earn lawfully and forbidden from earning unlawfully, and all of it is by the decrees of Allah, all of it.
A person does not go outside the decree of Allah, but he is commanded to be scrupulous, commanded to seek good and avoid evil. Allah has given him intellect, He has given him choice by which he distinguishes between this and that. He is blamed if he leans toward the evils, toward disobedience, toward intoxicants, toward zina (unlawful sexual intercourse), and the like. And he is commended if he leans toward obedience, takes the path of obedience, and remains steadfast in obedience; because he has intellect, he has will, he has choice, and he has discernment by which he distinguishes between good and evil, benefit and harm, truth and falsehood. This is how the Shari'ah (Islamic sacred law) came, and this is how Allah (Exalted and Majestic is He) decreed and determined for His servants, and He gave them distinguishing intellects by which they distinguish between truth and falsehood, guidance and rightness, and error and rightness, and the like.