It is narrated from Hazrat Anas (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: The supplication made between the call to prayer (Adhan) and the commencement (Iqamah) is not rejected, so make supplication at that time.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 13357
Hadith Gradingحکم دارالسلام:حديث صحيح، وهذا إسناد حسن.