Hadith 764

حَدَّثَنَا عَلِيُّ بْنُ عَبْدِ اللهِ، قَالَ‏:‏ حَدَّثَنَا سُفْيَانُ قَالَ‏:‏ قَالَ عَمْرٌو‏:‏ عَنِ ابْنِ عَبَّاسٍ‏:‏ لاَ يَقُولَنَّ أَحَدُكُمْ لِشَيْءٍ لاَ يَعْلَمُهُ‏:‏ اللَّهُ يَعْلَمُهُ ؛ وَاللَّهُ يَعْلَمُ غَيْرَ ذَلِكَ، فَيُعَلِّمَ اللَّهَ مَا لاَ يَعْلَمُ، فَذَاكَ عِنْدَ اللهِ عَظِيمٌ‏.‏
It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them) that he said: None of you should say about something he does not know, "Allah knows it." Allah knows more than that, but then that person includes in Allah's knowledge something the reality of which he himself does not know. This is a very great sin in the sight of Allah.
Hadith Reference الادب المفرد / كتاب الأقوال / 764
Hadith Grading الألبانی: صحيح
Hadith Takhrij «صحيح : أخرجه عبدالرزاق : 15964»