Madan said, I met Thawban, the freed slave of the Messenger of Allah ﷺ, and said to him, "Tell me of a deed I can do that will cause Allah to admit me into Paradise," or he said, I asked, "Tell me of the deed most beloved to Allah."He remained silent. I asked him again, and he remained silent. Then I asked him a third time.He replied, "I asked the Messenger of Allah ﷺ about that, and he said, 'You must prostrate often to Allah, for you do not perform a single prostration to Allah without Allah raising you a degree by it and erasing a sin from you because of it.'"Madan continued, Then I met Abu Darda and asked him the same question, and he gave me the same answer Thawban had given me.
لقيت ثوبان مولى رسول الله ﷺ فقلت: أخبرني بعمل أعمله يدخلني الله به الجنة، أو قال: قلت: بأحب الأعمال إلى الله. فسكت ثم سألته فسكت، ثم سألته الثالثة. فقال: سألت عن ذلك رسول الله ﷺ فقال: عليك بكثرة السجود الله. فإنك لا تسجد لله سجدة إلا رفعك الله بها درجة، وحط عنك بها خطيئة. قال معدان: ثم لقيت أبا الدرداء فسألته. فقال لي مثل ما قال لي ثوبان.