(a) Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrates that the Messenger of Allah (peace and blessings be upon him) would lengthen the recitation in the two rak'ahs after the Maghrib prayer so much that the people of the mosque (having finished their prayer) would leave.
(b) Shaykh al-Bayhaqi (may Allah have mercy on him) says: He (peace and blessings be upon him) did this for some period, and what Sayyiduna Ibn Umar (may Allah be pleased with them both) narrated about offering the two rak'ahs of Maghrib in his house was also for a period. 'Wa billahi al-tawfiq' (And success comes only from Allah).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3042