Musnad Ahmad 658:51

'Affan narrated to us, Shu'bah narrated to us, he said: Talhah informed me, he said: I heard 'Abd al-Rahman ibn 'Awsajah, from al-Bara' ibn 'Azib, from the Prophet, peace and blessings of Allah be upon him, who said: "Whoever grants a gift of silver, or lends silver, or guides someone to a path, or gives milk to drink, it is for him equivalent to the freeing of a slave or a soul. And whoever says: 'There is no god but Allah alone, He has no partner, to Him belongs the dominion and to Him belongs the praise, and He is capable of all things,' ten times, it is for him equivalent to the freeing of a slave or a soul." He said: And he used to come to us when we stood for prayer, and he would touch our shoulders or our chests, and he used to say: "Do not differ, for your hearts will differ." And he used to say: "Indeed, Allah and His angels send blessings upon the first row, or the first rows."