It is narrated from Sayyidah Umm Salamah (may Allah be pleased with her); she said: The Messenger of Allah (peace and blessings be upon him) said to me: "At the time of the adhan of Maghrib, say: 'Allahumma 'inda iqbali laylika wa idbari naharika wa aswati du'atika wa huduri salawatika ighfir li' (O Allah, at the coming of Your night, the departing of Your day, the voices of those who call to You and the arrival of Your prayers, forgive me)." And when she woke during the night, she would say: 'Rabbi ighfir warham wahdi al-sabil al-aqwam' (My Lord, forgive, have mercy, and guide to the most upright path).
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19984