Musnad Ahmad 658:232

Yahya and Muhammad ibn Ja’far narrated to us, they said: Shu’bah narrated to us, he said: Talhah ibn Musarrif narrated to us, from ‘Abd al-Rahman ibn ‘Awsajah, from al-Bara’ ibn ‘Azib, who said: Ibn Ja’far said: Shu’bah narrated to us, he said: I heard Talhah al-Yami, he said: I heard ‘Abd al-Rahman ibn ‘Awsajah, he said: I heard al-Bara’ ibn ‘Azib narrating from the Prophet, may Allah bless him and grant him peace, who said: "Whoever grants a gift of silver, or guides someone along a path, or provides a drink of milk, it shall be 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 shall be for him equivalent to the freeing of a slave or a soul." He used to come to us when we stood for prayer, and he would wipe our chests or our shoulders, saying: "Do not differ in your rows, lest your hearts differ." And he used to say: "Indeed, Allah and His angels send blessings upon the first row, or the first rows." And he said: "Beautify the Quran with your voices." I had forgotten it, and al-Dahhak ibn Muzahim reminded me of it.