Al-Kāfi - Volume 2 > Truthfulness and Trust
Hadith #12

12ـ عَنْهُ عَنْ أَبِي طَالِبٍ رَفَعَهُ قَالَ قَالَ أَبُو عَبْدِ الله (عَلَيهِ السَّلام) لا تَنْظُرُوا إِلَى طُولِ رُكُوعِ الرَّجُلِ وَسُجُودِهِ فَإِنَّ ذَلِكَ شَيْ‏ءٌ اعْتَادَهُ فَلَوْ تَرَكَهُ اسْتَوْحَشَ لِذَلِكَ وَلَكِنِ انْظُرُوا إِلَى صِدْقِ حَدِيثِهِ وَأَدَاءِ أَمَانَتِهِ.

12. It is narrated from him (narrator of the Hadith above) from abu Talib in a marfu’ manner from abu ‘Abd Allah (a.s.) who has said the following: “Abu ‘Abd Allah (a.s.) has said, ‘Do not look to the long Ruku’ (bowing down on one’s knees for prayer) and Sajda (prostrating in prayer) of a man. It may have become his routine; without it he may feel frightened, but look to the truthfulness in his words and his credibility in keeping the trust.’”