Narrated An-Nu'man bin Bashir:
from the Prophet (ﷺ) regarding Allah's saying: Your Lord said: Invoke Me, I shall respond to you (40:60, it appears that the author intended to apply it to Al-Baqarah 2:186). - he said: "The supplication is the worship." And he recited: 'Your Lord said: Invoke Me, I shall respond to you.' up to His saying: 'in humiliation.'" (DE)
English reference (DE): Vol. 5, Book 44, Hadith 2969 (DE)
Arabic reference (DE): Book 47, Hadith 3232 (DE)