The word: يَدَّعُونَ (yadda’ un) appearing in verse 57: وَلَهُم مَّا يَدَّعُونَ (wa lahum ma yadda un) is a derivation from: دَعوَیٰ (da'wah) which means to call, that is, the thing the people of Jannah will call or wish to have, will come to them. The Qur'an has not used the word: يَسْأَلُونَ Yas’ alun: they ask) at this place, because having something after having asked for it is also a sort of exertion, something the Jannah will be free from, in fact, it will be a place where everything needed will be ready and present.