(327) بَابُ لا يَقُولُ لِشَيْءٍ لا يَعْلَمُهُ: اللَّهُ يَعْلَمُهُ
Ibn 'Abbas said, "None of you should say about a thing which hedoes not know, 'Allah knows it' when Allah may know that it is other thanwhat he said and thus he (tries to) teach Allah what he does not know.That is something terrible in Allah's sight."
Reference: Al-Adab Al-Mufrad 764
In-book reference: Book 33, Hadith 11
English translation: Book 33, Hadith 764