Sunan Ibn Majah 3828
سنن ابن ماجه#3828SahihIt was narrated from Nu'man bin Bashir that :the Messenger of Allah (saas) said: "Indeed the supplication is the worship." Then he recited: "And your Lord said: Invoke Me, I will respond to you
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Fouad Abd al-BaqiSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih
In-book reference: 34:2