The word is derived from katan, which means thickness and greasiness. It refers to the flaxseeds which are so rich in oil that they may turn rancid when left for a while. Flax is annual plant of the Linaceae family. Flaxseeds are considered to have a high nutritional value, as they contain a huge amount of carbohydrates, proteins, and oils.
“Muhammad bin Sirin said:
“”We were with Abu Hurairah and he was wearing two linen garments dyed with red ochre. He blew his nose in one of them and said: ‘Excellent! Abu hurairah blows his nose in linens! I saw a time when I would pass out between the mimbar of the Prophet (PBUH) and the dwelling of ‘Aishah from overwhelming hunger. Someone came and placed his foot on my neck thinking that I was a mad man, but I was not crazy, It was nothing but hunger.”” (narrated by At-Tirmidhiyy)”