Full Sharh — Mishkat al-Masabih 831
وَعَن النُّعْمَان بن مرّة أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: مَا تَرَوْنَ فِي الشَّارِبِ وَالزَّانِي وَالسَّارِقِ؟ " وَذَلِكَ قَبْلَ أَنْ تُنْزَلَ فِيهِمُ الْحُدُودُ قَالُوا: اللَّهُ وَرَسُولُهُ أَعْلَمُ. قَالَ: «هُنَّ فَوَاحِشُ وَفِيهِنَّ عُقُوبَةٌ وَأَسْوَأُ السَّرِقَةِ الَّذِي يَسْرِقُ مِنْ صَلَاتِهِ» . قَالُوا: وَكَيف يسرق م صَلَاتِهِ يَا رَسُولَ اللَّهِ؟ قَالَ: «لَا يُتِمُّ ركوعها وَلَا سجودها» . رَوَاهُ مَالك وَأحمد وروى الدَّارمِيّ نَحوه
English Translation
An-Nu‘man b. Murra reported God’s Messenger as saying, “What do you think of the drinker, the fornicator, and the thief?” That was before the prescribed punishments regarding them were revealed. On receiving the reply that God and His Messenger knew best, he said, “Such sins are abominations and punishment is prescribed for them, but the worst theft is what one steals from his prayer.” He was asked how one could steal from his prayer and replied, “By not performing his bowing and his prostration perfectly.” Malik and Ahmad transmitted it, and Darimi transmitted something similar.
Source
Mishkat al-Masabih(مشكاة المصابيح)
Prayer
Hadith Number
831