You are reading a tafsir for the group of verses 21:78 to 21:80
وَدَاوٗدَ
وَسُلَیْمٰنَ
اِذْ
یَحْكُمٰنِ
فِی
الْحَرْثِ
اِذْ
نَفَشَتْ
فِیْهِ
غَنَمُ
الْقَوْمِ ۚ
وَكُنَّا
لِحُكْمِهِمْ
شٰهِدِیْنَ
۟ۗۙ
فَفَهَّمْنٰهَا
سُلَیْمٰنَ ۚ
وَكُلًّا
اٰتَیْنَا
حُكْمًا
وَّعِلْمًا ؗ
وَّسَخَّرْنَا
مَعَ
دَاوٗدَ
الْجِبَالَ
یُسَبِّحْنَ
وَالطَّیْرَ ؕ
وَكُنَّا
فٰعِلِیْنَ
۟
وَعَلَّمْنٰهُ
صَنْعَةَ
لَبُوْسٍ
لَّكُمْ
لِتُحْصِنَكُمْ
مِّنْ
بَاْسِكُمْ ۚ
فَهَلْ
اَنْتُمْ
شٰكِرُوْنَ
۟
3

In these verses two Israelite prophets have been mentioned—One David (Dawud) and the other, his son, Soloman (Sulayman). God had bestowed upon them the capability to settle human problems and take right decisions about them. The Prophet David used to offer prayers to God so eloquently that even the mountains and the birds would join in with him. Moreover, God also told him how to make use of iron. It was the prophets of God who taught man how to pray to his Lord and praise Him. But it appears from these verses that other important things also came to be properly known to man through the prophets: for instance, the principles of social justice and the use of minerals and metals. Indeed, primary knowledge of every important thing in relation to life was probably granted to man through their good graces alone.