"O people, you eat of two plants which I do not think are anything but bad, this onion and garlic. I have seen the Prophet of Allah ﷺ, if he noticed their smell coming from a man, ordering that he be taken out to Al-Baqi'. Whoever eats them, let him cook them to death." (Using translation from Nasāʾī 708)  

«إِنَّكُمْ أَيُّهَا النَّاسُ تَأْكُلُونَ مِنْ شَجَرَتَيْنِ مَا أَرَاهُمَا إِلَّا خَبِيثَتَيْنِ هَذَا الْبَصَلُ وَالثُّومُ لَقَدْ رَأَيْتُ نَبِيَّ اللهِ ﷺ إِذَا وَجَدَ رِيحَهُمَا مِنَ الرَّجُلِ أَمَرَ بِهِ فَأُخْرِجَ بِهِ إِلَى الْبَقِيعِ فَمَنْ أَكَلَهُمَا فَلْيُمِتْهُمَا طَبْخًا»