It is narrated from Sayyidah Aisha (may Allah be pleased with her) that the Noble Prophet (peace and blessings be upon him) had two muezzins: Bilal and the son of Umm Maktum. So the Messenger of Allah (peace and blessings be upon him) said: "Bilal gives the call to prayer during the night, so keep eating and drinking until you hear the call to prayer of Ibn Umm Maktum." Qasim said: There was such an interval between their calls to prayer that one would descend and the other would ascend (for the call to prayer).
Hadith Referenceسنن دارمي / من كتاب الصللاة / 1224
Hadith Gradingتحقیق (حسین سلیم أسد الدارانی):حديث ابن عمر متفق عليه، [مكتبه الشامله نمبر: 1227]
Hadith Takhrijیہ حدیث صحیح ہے۔ دیکھئے: [بخاري 622] ، [مسلم 1092/38] و [صحيح ابن حبان 3473]