Quran mentions in two separate places the grave sin of killing one’s own kids.

In Surah 6 Al-An’am, verse 151: “..And do not kill your children out of poverty; We will provide for you and them..”

Note in this verse two things: (1) The killing is because of a poverty which is already affecting the parents. (2) Allah promises to provide first the parents and then the children.

 
In Surah 17 – Al-Isra’ verse 31:

“And do not kill your children for fear of poverty. We provide for them and for you.”

Here comes the beauty of Quranic style. In this verse the killing is not out of a present poverty, rather it is the fear of a future poverty (in contrast to point (1) in the first verse), hence, the promise to provide the children first (in contrast to point (2) in the first verse).

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