He who hoards is a sinner. It was said to Saʿid (b. al-Musayyib): You also hoard. Saʿid said: Maʿmar who narrated this hadith also hoarded.  

قَالَ رَسُولُ اللَّهِ ﷺ مَنِ احْتَكَرَ فَهُوَ خَاطِئٌ فَقِيلَ لِسَعِيدٍ فَإِنَّكَ تَحْتَكِرُ قَالَ سَعِيدٌ إِنَّ مَعْمَرًا الَّذِي كَانَ يُحَدِّثُ هَذَا الْحَدِيثَ كَانَ يَحْتَكِرُ  

The Messenger of Allah ﷺ as saying: No one withholds goods till their price rises but a sinner. I said to Sa'id (b. al-Musayyab): You withhold goods till their price rises. He said: Ma'mar used to withhold goods till their price rose. Abu Dawud said: I asked Ahmad (b. Hanbal): What is hoarding (hukrah) ? He replied: That on which people live. Abu Dawud said: Al-Auza'i said: A muhtakir (one who hoards) is one who withholds supply of goods in the market.  

قَالَ رَسُولُ اللَّهِ ﷺ لاَ يَحْتَكِرُ إِلاَّ خَاطِئٌ فَقُلْتُ لِسَعِيدٍ فَإِنَّكَ تَحْتَكِرُ قَالَ وَمَعْمَرٌ كَانَ يَحْتَكِرُ  

From Sa'eed bin Al-Musayyab, from Ma'mar bin 'Abdullah bin Nadlah who said: "I heard the Messenger of Allah ﷺ saying: 'Hoarding is nothing but sin.' So I (Muhammad) said to Sa'eed: "O Abu Muhammad! You hoard?" He said: "And Ma'mar would hoard." It is also been reported that Sa'eed bin Musayyab would hoard oil, (camel) fodder, and the like.  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ لاَ يَحْتَكِرُ إِلاَّ خَاطِئٌ فَقُلْتُ لِسَعِيدٍ يَا أَبَا مُحَمَّدٍ إِنَّكَ تَحْتَكِرُ قَالَ وَمَعْمَرٌ قَدْ كَانَ يَحْتَكِرُ