“Whoever says ten times: ‘None has the right to be worshipped by Allah, Alone, without partner, to Him belongs all that exists, and to Him belongs the praise, wa huwa `alā kulli shai’in qadīr)’ it is for him equal to freeing four slaves among the offspring of Isma`il.”
Jami` at-Tirmidhi Book 48, Hadith 184