It is narrated from Hazrat Mutlib (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: (Nafl) prayer is performed in sets of two rak'ahs; after every two rak'ahs, recite the tashahhud, express your needs and humility, and spread your hands and say, "O Allah! O Allah!" and make supplication. Whoever does not do so, his prayer is incomplete.