Abu Dujanah on Work: Most reliable deeds are purity of heart and speech

Zayd ibn Aslam reported: They entered the home of Abu Dujanah, may Allah be pleased with him, while he was sick but his face was joyful. It was said to him, “Why is your face joyful?” Abu Dujanah said, “There is no work more reliable to me than two things: that I do not speak of what does not concern me, and that my heart is pure towards the Muslims.”

Source: Siyar A’lām al-Nubalā’ 1/243

عن زَيْد بْن أَسْلَم دُخِلَ عَلَى أَبِي دُجَانَةَ رَضِيَ اللَّهُ عَنْهُ وَهُوَ مَرِيضٌ وَكَانَ وَجْهُهُ يَتَهَلَّلُ فَقِيلَ لَهُ مَا لِوَجْهِكَ يَتَهَلَّلُ فَقَالَ مَا مِنْ عَمَلِ شَيْءٍ أَوْثَقَ عِنْدِي مِنَ اثْنَتَيْنِ كُنْتُ لَا أَتَكَلَّمُ فِيمَا لَا يَعْنِينِي وَالْأُخْرَى فَكَانَ قَلْبِي لِلْمُسْلِمِينَ سَلِيمًا

1/243 سير أعلام النبلاء الصحابة رضوان الله عليهم أبو دجانة الأنصاري