Hadith 34

يَدْعُو لِنَفسِهِ بَيْنَ الْأَذَانِ وَالْإِقَامَةِ فَإِنَّ الدُّعَاءَ حِينَئِذٍ لاَ يُرَدُّ
Between the call to prayer and the 'Iqamah, you should supplicate Allah for yourself. Invocation during this time is not rejected.
Hadith Reference Hisnul Muslim / Chapters / Hadith: 34