[His saying, the Exalted: "And those who are firm in knowledge"]
[The First Aspect]
3205 - Muhammad b. 'Awf al-Himsi narrated to us, Nu'aym b. Hammad reported to us, Fayyad al-Raqqi reported to us, 'Abd Allah b. Yazid reported to us—who had met the companions of the Prophet, peace and blessings of Allah be upon him: Abu Umamah, Anas, and Abu al-Darda'. He said: Abu al-Darda' reported that the Messenger of Allah, peace and blessings of Allah be upon him, was asked about those who are firm in knowledge, and he said: "Whoever has an upright oath, a truthful tongue, a steadfast heart, and who guards his stomach and his private parts, he is among those who are firm in knowledge."
The Second Aspect:
3206 - 'Abd Allah b. Sa'id al-Ashajj narrated to us, Abu Tumaylah reported to us, Abu Munib informed us, from Abu al-Sha'tha' and Abu Nahik regarding His saying: "but no one knows its [true] interpretation except Allah and those who are firm in knowledge," he said: You are connecting this verse while it is [actually] disconnected. Then he recited: "And those who are firm in knowledge say: 'We believe in it, all of it is from our Lord,'" and He praised them until His saying: "those who said 'but no one knows its [true] interpretation except Allah.'" Then He said: "And those who are firm in knowledge say: 'We believe in it.'"
3207 - Yunus b. 'Abd al-A'la informed us by way of reading, Ibn Wahb reported to us, and Ibn Abi al-Zinad informed me, Hisham—meaning Ibn 'Urwah—reported to us: My father used to say regarding this verse: "And those who are firm in knowledge say: 'We believe in it,'" he said: Indeed, those who are firm in knowledge do not know its [true] interpretation, but they say: "We believe in it; all of it is from our Lord."
3208 - My father narrated to us, Yasarah b. Safwan reported to us, Nafi' b. 'Umar al-Jumahi reported to us, from Ibn Abi Mulaykah, he said: 'A'ishah recited these verses: "It is He who has sent down to you the Book," up to His saying: "We believe in it." She said: It was of their firmness in knowledge that they believed in its clear verses and its ambiguous verses, while they do not know them.
The Third Aspect:
3209 - 'Abd Allah b. Sulayman al-Ash'ath narrated to us, Hammu b. Nuh reported to us, Abu Mu'adh reported to us, Abu Muslih reported to us, from al-Dahhak: "but no one knows its [true] interpretation except Allah and those who are firm in knowledge."
(1). Al-Haythami said: And 'Abd Allah b. Yazid is weak—Al-Zawa'id 6/324.