Sayyiduna Abu Umamah (may Allah be pleased with him) said: Sayyidah Umm Hani (may Allah be pleased with her) asked the Messenger of Allah (peace and blessings be upon him), saying: O Messenger of Allah, I am a woman who has grown heavy (with age), so teach me some words by which Allah will benefit me. He (peace and blessings be upon him) said: "Say: Subhan Allah a hundred times; this equals freeing a hundred slaves in the way of Allah. Say Alhamdulillah a hundred times; this equals giving a hundred bridled horses in the way of Allah. Say Allahu Akbar a hundred times; this equals sending a hundred garlanded sacrificial animals as an offering to the House of Allah. And say La ilaha illallah a hundred times; then no sin will overtake you after shirk (associating partners with Allah)."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7993