Muslim narrated in his Sahih from Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (may Allah bless him and give him peace) said he who invokes blessings on me once, Allah sends ten blessings upon him.
Al-Nasai narrated in Invocations of the day and night, from Umar bin Dinar (may Allah be pleased with him) that the Prophet (may Allah bless him and give him peace) said he of my community who invokes blessings upon me sincerely, Allah will bless him ten fold and raise him ten degrees, and he will have written for him ten good deeds, and erased from his record ten bad deeds.
Tirmidhi narrated that Umar ibn al-Khattab (may Allah be pleased with him) said Verily, supplications are stalled between the heavens and the earth, and are not lifted up until the supplicant invokes blessings upon the Prophet (may Allah bless him and give him peace).
Tirmidhi related from Abdullah bin Masud (may Allah be pleased with him) that the Messenger of Allah (may Allah bless him and give him peace) said the closest people to me on the Day of Resurrection will be those who invoked the most blessings upon me.
Tirmidhi narrated from Amir bin Raniah (may Allah be pleased with him) that the Prophet (may Allah bless him and give him peace) said he who invokes blessings upon me, the Angels send blessings upon him equal to that which he invoked, so let the worshipper invoke some, or increase upon that.