Jami` at-Tirmidhi Book 48, Hadith 226
“The supplication is not rejected between the Adhan and the Iqamah.”
“The supplication is not rejected between the Adhan and the Iqamah.” They said: “So what should we say, O Messenger of Allah (ﷺ)?” He said: “Ask Allah for Al-`Afiyah in the world and in the Hereafter.”
“The Mufarridun have preceded.” They said: “And who are the Mufarridun, O Messenger of Allah (ﷺ)?” He said: “Those who absorb themselves in the remembrance of Allah, and remembrance removed their heavy burdens from them, until they will come on the Day of Judgement being light (in weight of their burdens).”