It is narrated from Sayyiduna Sahl bin Sa'd (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "There is no prayer for one who has no ablution (wudu); there is no ablution for one who does not mention the name of Allah over it; there is no prayer for one who does not send blessings upon the Prophet (peace and blessings be upon him); and there is no prayer for one who does not love the Ansar."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5678