Hoarding

1. If anyone keeps goods till the price rises, he is a sinner.
(Muslim).

2. He who brings goods for sale is blessed with good fortune, but he who keeps them till the price rises is accursed.
(Ibn Majah, Darimi).

3. If anyone withholds grain for forty days thereby desiring a high price, has renounced Allah and Allah has renounced him.
(Razin).

4. The man who withholds goods is evil. If Allah lowers prices he is grieved, and if He raises then he is happy. 
(Baihaqi).