Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: If dinner is served and the time for prayer also comes, then eat the food first, and then offer the Maghrib prayer afterwards.
Hadith Referenceالمنتقى ابن الجارود / كتاب الصلاة / 223