Hadithcore
Al-Adab Al-Mufrad, 636
da’if· Al-Albani

The Prophet, (ﷺ), said, "If someone says, 'There is no god but Allah' one hundred times, 'Glory be to Allah' one hundred times' and 'Allah is greater' one hundred times, that is better than freeing ten slaves and slaughtering seven camels."

وَقَالَ النَّبِيُّ صلى الله عليه وسلم‏:‏ مَنْ هَلَّلَ مِئَةً، وَسَبَّحَ مِئَةً، وَكَبَّرَ مِئَةً، خَيْرٌ لَهُ مِنْ عَشْرِ رِقَابٍ يُعْتِقُهَا، وَسَبْعِ بَدَنَاتٍ يَنْحَرُهَا‏.‏

References2 variants
In-Book Reference
Book 31, Hadith 33
English Reference
Book 31, Hadith 636