Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) narrates this statement of the Noble Prophet (peace and blessings of Allah be upon him): "Sayyiduna Musa (peace be upon him) submitted: O my Lord, teach me something through which I may remember You, with which I may supplicate to You. Allah Almighty said: O Musa, recite this: There is no deity except Allah. Sayyiduna Musa (peace be upon him) submitted: O my Lord, all Your servants recite this phrase. Allah Almighty said: You recite La ilaha illallah. Sayyiduna Musa (peace be upon him) submitted: I desire something that is special for me. Allah Almighty said: O Musa, if the inhabitants of the seven heavens and the inhabitants of the seven earths were placed on one side of the scale, and La ilaha illallah was placed on the other side, the side with La ilaha illallah would outweigh."
Hadith Referenceصحیح ابن حبان / كتاب التاريخ / 6218
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيضعيف - «التعليق الرغيب» (2/ 238 - 239).فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده ضعيف