Please provide the Hadith-e-Khudsi that states that Allah s.w.t. answers/responds to every Ayat of Surat Fatiha we recite in every Rakaat of Salaat.

Abu Hurayra [Radhiallaahu anhu] narrates from Rasulullah [Sallallaahu Alayhi Wasallam] that Allah Ta'ala states, 'I have distributed the Salaat equally between myself and my servant and for my servant is what he asks. When the servant says, 'Alhamdulillaahi rabbil aalamee', Allah Ta'ala says, 'My servant has praised me.' And when he says, 'ar-rahmaanir raheem', Allah Ta' ala says, 'My servant has commended me.' When he says, 'Maalik yawmid-deen', Allah says, 'My servant has glorified me.' And sometimes, Allah says 'My servant has entrusted me with all his affairs.'

When he says, 'Iyyaaka na'abudu, wa iyyaaka nasta'een', Allah says, 'This is between me and my servant.' When he says, 'Ihdinas-siraatal mustaqeem. Siraatal ladheena an'amta alayhim. Ghayril maghdhoob alayhim walad-dhaalleen ', Allah says, 'This is for my servant and for my servant is what he seeks.' (Muslim vol.3 pg.324-325)

and Allah Ta'ala Knows Best