The Messenger of Allah ﷺ said, "Supplication made between the adhan and the iqamah is not rejected, so make supplication."
قال رسول الله ﷺ: إن الدعاء لا يرد بين الأذان والإقامة فادعوا.
Reported by Abu Dawud (521), Tirmidhi (212), and Nasai in Al-Yawm wal-Laylah (68, 69, 70), all of them through various routes from Zayd Ammi, from Abu Iyas, from Anas bin Malik, who related the hadith. Tirmidhi said, "Hasan," though in one manuscript it reads "Hasan sahih," and the first reading is closer to correct, because its chain contains Zayd Ammi, that is Zayd bin Hawari, Abu Hawari Basri. There is disagreement about the reason for this nickname. Some said he was named after "Banu Amm," a clan of Banu Tamim, while Ali bin Musab said he was called Ammi because whenever he was asked about something he would say, "Until I ask my uncle (ammi)." He is daif, as Abu Hatim, Nasai, Ibn Saad, and Ibn Madini all judged him daif. Ibn Hibban said, "He narrates fabricated hadiths from Anas that have no basis." A narrator like this cannot have his hadith graded hasan, let alone sahih.However, this hadith has other supporting routes, and for that reason I have included it in the Jami. Among these routes is what Imam Ahmad reported in his Musnad (12584), saying, Aswad and Husayn bin Muhammad told us, they said, Israil told us, from Abu Ishaq, from Burayd bin Abu Maryam, from Anas, who related the hadith. Abu Yaala (3679) also reported it through the route of Israil with the same wording. Tirmidhi alluded to this, saying, "Abu Ishaq Hamdani has also reported it from Burayd bin Abu Maryam, from Anas, from the Prophet ﷺ, in similar wording."Abu Ishaq here is Amr bin Abdullah Sabi, well known by his kunya, a trustworthy successor, though he used to practice tadlis. However, his son Yunus corroborated him, for Imam Ahmad (13357) reported it from Ismail bin Umar, who said, Yunus, that is the son of Abu Ishaq, told us, he said, Burayd bin Abu Maryam told us, from Anas, who related the hadith. Yunus bin Abu Ishaq is truthful. This same route was also reported by Ibn Khuzayma in his Sahih (426, 427), and he said this refers to the supplication that is answered.Aswad here is Ibn Amir, nicknamed Shazan, a trustworthy narrator among the men relied upon by the community of scholars. Husayn bin Muhammad is Ibn Bahram Maruzi, with the waw doubled and the dhal pointed, also trustworthy among the men relied upon by the community. This is among the finest chains through which this supplication has been narrated. I know of no sahih hadith on this subject other than the hadith of Anas.Abu Yaala (4072) also reported it from Ibrahim bin Hajjaj, who said, Sahl bin Ziyad told us, from Taymi, from Anas, that the Messenger of Allah ﷺ said, "When the call is made for prayer, the gates of heaven are opened and supplication is answered." Sahl bin Ziyad is Abu Ziyad Tahhan, about whom Azdi said, "Sahl bin Ziyad, narrating from Sulayman Taymi and those of his level, has munkar hadith." Lisan Mizan (405).Tayalisi (2220) also reported it from Rabi, from Yazid, from Anas, in similar wording. Yazid here is Ibn Aban Raqashi Basri, who is daif, and Haythami faulted the hadith on this basis in Al-Majma (1/334).