Anas said, "The Prophet ﷺ prayed in the sheep fold." Later on I heard him saying, "He prayed in the sheep folds before the construction of the, mosque."  

كَانَ النَّبِيُّ ﷺ يُصَلِّي فِي مَرَابِضِ الْغَنَمِ ثُمَّ سَمِعْتُهُ بَعْدُ يَقُولُ كَانَ يُصَلِّي فِي مَرَابِضِ الْغَنَمِ قَبْلَ أَنْ يُبْنَى الْمَسْجِدُ