Sayyiduna Abu Hurayrah (may Allah be pleased with him) relates that the poor among the Muslims came to the Messenger of Allah (peace and blessings be upon him) and said: "O Messenger of Allah! The people of wealth have taken the high ranks. They pray as we pray, fast as we fast, and perform Hajj as we perform Hajj, but they have surplus wealth from which they give charity, while we have nothing to give in charity." He (peace and blessings be upon him) said: "Shall I not tell you of something which, if you do it, you will catch up with those who have gone ahead of you, and those after you will not reach you, except someone who does the like of what you do? Say 'Subhan Allah' 33 times, 'Al-hamdu lillah' 33 times and 'Allahu akbar' 34 times after every prayer." This reached the wealthy, and they too began saying what the poor were saying. So they (the poor) came to the Messenger of Allah (peace and blessings be upon him) and informed him (peace and blessings be upon him), and he (peace and blessings be upon him) said: "That is the bounty of Allah; He grants it to whom He wills."
Hadith Referenceالمعجم الأوسط / باب الميم / 5310
Hadith Takhrij«أخرجه البخاري فى «صحيحه» برقم: 843، 6329، ومسلم فى «صحيحه» برقم: 595، وابن خزيمة فى «صحيحه» برقم: 749، وابن حبان فى «صحيحه» برقم: 2014، 2015، والنسائي فى «السنن الكبرى» برقم: 9898، وأبو داود فى «سننه» برقم: 1504، والدارمي فى «مسنده» برقم: 1393، والبيهقي فى «السنن الكبرى» برقم: 3071، 3072، 3073، 3074، وأحمد فى «مسنده» برقم: 7363، وأبو يعلى فى «مسنده» برقم: 6587، والبزار فى «مسنده» برقم: 8953، 8954، 8960، 9105، والطبراني فى «الصغير» برقم: 802، والطبراني فى «الأوسط» برقم: 299»