وَلَمَّا جَاءَهُمْ كِتَابٌ مِّنْ عِندِ اللَّهِ مُصَدِّقٌ لِّمَا مَعَهُمْ وَكَانُوا مِن قَبْلُ يَسْتَفْتِحُونَ عَلَى الَّذِينَ كَفَرُوا فَلَمَّا جَاءَهُم مَّا عَرَفُوا كَفَرُوا بِهِ ۚ فَلَعْنَةُ اللَّهِ عَلَى الْكَافِرِينَ
Wa lammaa jaaa'ahum kitaabum min 'indil laahi musaddiqul limaa ma'ahum wa kaanoo min qablu yastaftihoona 'alal lazeena kafaroo falammaa jaaa'ahum maa 'arafoo kafaroo bih; fala'natul laahi 'alal kaafireen
And when a scripture came to them from God, confirming what they already had — though before this they had prayed for victory over those who denied the truth — when there came to them what they recognized, they denied it. So God's curse is upon those who deny.
Yastaftiḥūn, the verb describing their earlier practice, means to seek an opening or a victory, and it shares a root with the word for conquest. The tragedy the verse constructs is recognition: what arrived was the thing prayed for and was known to be so, and the denial came after the recognition rather than instead of it. Confirmation is stated as the ground of the claim, not as a courtesy.