Surah Al-An'aam 6:140

Indeed lost are they who have killed their children, foolishly, without knowledge, and (they) have forbidden that which Allah has provided for them, inventing a lie against Allah. They have indeed gone astray and were not guided (140)

Allah says that those who committed these evil acts have earned the loss of this life and the Hereafter.

As for this life, they lost when they killed their children and made it difficult for themselves by prohibiting some types of their wealth, as an act of innovation that they invented on their own. As for the Hereafter, they will end up in the worst dwellings, because they used to lie about Allah and invent falsehood about Him. Allah also said,

إِنَّ الَّذِينَ يَفْتَرُونَ عَلَى اللَّهِ الْكَذِبَ لَا يُفْلِحُونَ - مَتَاعٌ فِي الدُّنْيَا ثُمَّ إِلَيْنَا مَرْجِعُهُمْ ثُمَّ نُذِيقُهُمُ الْعَذَابَ الشَّدِيدَ بِمَا كَانُوا يَكْفُرُونَ

(Say: "Verily, those who invent a lie against Allah will never be successful." (A brief) enjoyment in this world! And then unto Us will be their return, then We shall make them taste the severest torment because they used to disbelieve.)[10:69-70]

Al-Hafiz Abu Bakr bin Marduwyah recorded that Ibn 'Abbas commented, "If it pleases you to know how ignorant the Arabs used to be, then recite the Ayat beyond Ayah one hundred and thirty in Surat Al-An'am,

قَدْ خَسِرَ الَّذِينَ قَتَلُوا أَوْلَادَهُمْ سَفَهًا بِغَيْرِ عِلْمٍ وَحَرَّمُوا مَا رَزَقَهُمُ اللَّهُ افْتِرَاءً عَلَى اللَّهِ قَدْ ضَلُّوا وَمَا كَانُوا مُهْتَدِينَ

(Indeed lost are they who have killed their children, foolishly, without knowledge, and [they] have forbidden that which Allah has provided for them, inventing a lie against Allah. They have indeed gone astray and were not guided.)" Al-Bukhari also recorded this in the section of his Sahih on the virtues of the Quraysh.