Mishkat al-Masabih 897
Ma'dan b. Talha said:
I met Thauban the client of God’s Messenger and asked him to tell me something I should do for which God would bring me into paradise. He gave no reply, so I asked him again, and when he still gave no reply I asked him a third time. He then said that he had asked God’s Messenger about that and received the reply, “Make frequent prostration before God, for you will not make one prostration without God raising you a degree because of it and removing a sin from you because of it.” Ma'dan said that he met Abud Darda’ later, and that when he asked him he received a reply similar to that given by Thauban. 

Muslim transmitted it.
وَعَنْ مَعْدَانَ بْنِ طَلْحَةَ قَالَ: لَقِيتُ ثَوْبَانَ مَوْلَى رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقلت: أَخْبِرْنِي بِعَمَلٍ أَعْمَلُهُ يُدْخِلُنِي اللَّهُ بِهِ الْجَنَّةَ فَسَكَتَ ثُمَّ سَأَلْتُهُ فَسَكَتَ ثُمَّ سَأَلْتُهُ الثَّالِثَةَ فَقَالَ: سَأَلْتُ عَنْ ذَلِكَ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقَالَ: «عَلَيْكَ بِكَثْرَةِ السُّجُودِ لِلَّهِ فَإِنَّكَ لَا تَسْجُدُ لِلَّهِ سَجْدَةً إِلَّا رَفَعَكَ اللَّهُ بِهَا دَرَجَةً وَحَطَّ عَنْكَ بِهَا خَطِيئَةً» . قَالَ مَعْدَانُ: ثُمَّ لَقِيتُ أَبَا الدَّرْدَاءِ فَسَأَلْتُهُ فَقَالَ لِي مِثْلَ مَا قَالَ لِي ثَوْبَانُ. رَوَاهُ مُسلم